Restore the copied CMP design on course-facing pages

[alexeygrigorev]

Product decision

Restore the database-backed course experience to the visual composition copied from the Course Management Platform (CMP) at exact source commit 98a235283904b4ef9ad29e196298540756cf1bcc. The copied CMP course templates are the visual source of truth. Website integration may extend the shared shell for canonical same-host navigation, accessibility, security, and route compatibility, but it must not replace or redesign the composition of learner/course pages.

The rest of the public website continues to use the adopted CMP shell, tokens, typography, spacing, responsive behavior, and controls through the shared base. This urgent issue removes the course-specific redesign; it does not introduce another visual system.

Normative authority

• _docs/PROCESS.md
• _docs/specs/01-platform-architecture.md: one Django deployment and Django-template presentation
• _docs/specs/04-courses-and-cohorts.md: adopt and evolve CMP in place; preserve course discovery and learner behavior
• _docs/specs/10-verification-strategy.md: focused Django/contract/browser checks and inspected desktop/mobile evidence
• _docs/adoption/course-platform/README.md and integration-patches.md: pinned source ledger and explicit-overlay policy

Confirmed cause and baseline

website/settings/base.py configures template directories in this order:

1. course_platform_templates/;
2. project-level templates/;
3. installed-app template directories through APP_DIRS=True.

The clickable skeleton in #97 added templates/courses/course_list.html. It is therefore selected before Django reaches the copied courses/templates/courses/course_list.html. The shadow adds a Course-family promotion block, page-specific metadata, and changed empty-state copy. That is the observed composition change.

The copied destination itself is already correct and must not be rewritten:

• pinned CMP courses/templates/courses/course_list.html: SHA-256 26e391ffdd2c90b89a668c41118f4a8e43efd2b5dde015097f893aee707984ef;
• current website courses/templates/courses/course_list.html: the same SHA-256;
• current project shadow templates/courses/course_list.html: SHA-256 7b41e1f4f130d37630089ec62799734ef6283ea6198aae58972daa55b7200ac5.

A complete logical-name comparison found exactly one project-level collision among all 25 pinned courses/templates/** templates: courses/course_list.html. templates/public/course_hub.html is not a collision; it is the separate empty-database public projection used by content.public_views.course_hub when there are no adopted Course rows.

Scoped implementation

1. Remove templates/courses/course_list.html from the rendering path by deleting that project-owned shadow. Do not copy its additions into the adopted template.
2. Keep courses/templates/courses/course_list.html byte-identical to the pinned CMP source and keep all 25 logical templates beneath pinned courses/templates/** protected from higher-precedence project/app shadows.
3. Add a fail-closed adoption test that derives the protected logical names from the pinned copy ledger, rejects any templates/<logical-name> collision, and proves django.template.loader.get_template() resolves each protected name to its recorded copied destination under the actual unified settings.
4. Record the visual-source/no-shadow rule in the adoption integration documentation. A necessary future change to a copied course template must be an in-place, readable overlay recorded with source hash, target hash, narrow rationale, and focused tests; a parallel higher-precedence redesign is not an allowed integration mechanism.
5. Add focused database-backed browser coverage for the copied catalog branch and retain the separate no-database public-catalog coverage.

Allowed integration deltas

The rollback must preserve the existing, recorded shared integration layer, including:

• the CMP-derived course_platform_templates/base.html shell;
• production canonical URLs and same-host public navigation;
• one shared account menu, login/session behavior, and capability-gated Studio entry;
• skip link, focus/current-location semantics, form/error associations, keyboard behavior, responsive navigation, and reduced-motion support;
• local pinned static assets, security headers, CSRF/session protections, safe external-link semantics, and development noindex policy;
• route compatibility, /courses canonical behavior, and the Studio Courses namespace;
• narrowly recorded responsive fixes such as preventing long headers from widening the mobile viewport.

Those deltas may add shell semantics or safeguards. They must not add, remove, reorder, regroup, or restyle the page-specific sections/cards/content hierarchy of the copied CMP course templates. Do not revert an already recorded security/accessibility fix merely to obtain byte identity; the overlay ledger remains the explicit review boundary.

Acceptance criteria

• templates/courses/course_list.html is absent and no project-level or earlier app template shadows any of the 25 protected logical names from pinned courses/templates/**.
• courses/templates/courses/course_list.html remains readable, non-minified, and byte-identical to pinned CMP SHA-256 26e391ffdd2c90b89a668c41118f4a8e43efd2b5dde015097f893aee707984ef.
• Under the unified Django settings, every protected logical template resolves to its recorded adopted destination; the contract fails if a future project template silently wins loader precedence.
• With at least one visible database Course, canonical /courses renders the copied CMP course-list composition. The P0: Build a fully navigable Django review skeleton #97-only Course-family promotion and No active cohort coursework right now. copy are absent; the source active/open-registration/archive grouping and source empty-state copy remain.
• The no-Course branch still renders the existing read-only public catalog projection and its current Course-family/Cohort links; this fallback is not moved into or allowed to shadow copied CMP templates.
• The shared canonical navigation, account/login behavior, dark mode, accessibility semantics, security policy, local assets, route compatibility, and Studio Courses entry remain functional without changing CMP page composition.
• Existing database-backed course detail, registration/enrollment, dashboard, homework, project/peer-review, leaderboard, and certificate behavior does not regress.
• Course-facing template sources remain human-readable and line-broken; no generated/minified HTML replaces source templates.
• At approximately 1440×900 and 390×844, deterministic database-backed catalog screenshots match the pinned CMP section order, hierarchy, spacing, cards, controls, and visual language, apart from the explicitly allowed shared-shell integrations. Both have no horizontal overflow, clipping, missing stylesheet/font assets, console/page/request errors, debug page, or error page.
• The same desktop/mobile pass covers a representative copied course detail and navigation from catalog to detail; keyboard navigation, visible focus, dark mode, and 200% zoom/reflow remain usable.
• No model, migration, fixture, imported content, Course/Cohort behavior, public route, API, Studio mutation, or deployment configuration changes are introduced.

Focused verification

Django and adoption contracts

• Exercise core.tests.test_course_platform_adoption with the new protected-template origin/collision contract.
• Extend the focused homepage/course-hub tests to cover both branches: no database Course uses public/course_hub.html; a visible database Course uses the copied courses/course_list.html origin and source composition.
• Run uv run --frozen python scripts/verify_course_platform_adoption.py; all pinned source rows and explicit integration overlays must verify.
• Run the focused courses, content course-hub, shared-shell/accessibility, route/SEO, and template-readability Django tests plus makemigrations --check through uv/Make targets.
• Run git diff --check and the repository's applicable lint/format checks. There must be no model or migration diff.

Browser and screenshots

Use deterministic synthetic course data and no PII. At 1440×900 and 390×844:

1. Load canonical /courses through the database-backed branch; assert the copied source composition and absence of the P0: Build a fully navigable Django review skeleton #97-only promotion block/copy.
2. Traverse to a representative copied course detail and exercise the retained account/course navigation.
3. Check light/dark mode, keyboard focus, 200% zoom/reflow, local assets, console/page/request failures, and document/body overflow.
4. Store full-page evidence under .tmp/screenshots/issue-128/ and inspect every image. Record the pinned template hash and equivalent deterministic fixture with the screenshots so “CMP parity” is attributable to the exact source, not memory.
5. Run make test-playwright-core and the copied CMP browser workflow covering availability/provisioning, enrollment, homework, project/peer review, dashboards, and leaderboard.

The independent tester must compare the desktop/mobile candidate evidence with the exact pinned CMP composition and report the allowed shared-shell differences explicitly; “looks similar” is not sufficient.

Deployment gate

The existing read-only deployed smoke must capture /courses at desktop and mobile and assert the copied-composition markers, absence of the #97-only block, canonical/noindex policy, local assets, exact deployed identity, and no overflow/error state. On-call compares those deployed images with the accepted local CMP-parity evidence. If the deployed environment unexpectedly has no visible database Course and therefore cannot exercise the corrected branch, add human, leave #128 open with Refs #128, and obtain an authorized populated-development visual comparison rather than claiming the rollback is live. No owner-only HUMAN blocker is required while the populated deployed branch is exercised deterministically.

Expected implementation files

• Delete templates/courses/course_list.html.
• Update core/tests/test_course_platform_adoption.py for the 25-template fail-closed collision/origin contract and pinned course-list digest assertion.
• Update core/tests/test_homepage.py for explicit database-backed copied-template and unchanged empty-database fallback coverage.
• Update _docs/adoption/course-platform/integration-patches.md with the protected visual-source/no-shadow contract.
• Add focused browser parity coverage in playwright_tests/test_course_design_parity.py.
• Tighten the existing /courses assertions in playwright_tests/test_deployed_smoke.py.

Do not edit courses/templates/courses/course_list.html, models, migrations, views, URLconfs, Studio Courses, APIs, fixtures, or shared shell/CSS unless a failing acceptance check proves a strictly necessary allowed integration delta; any such expansion requires PM review before implementation continues.

Dependencies and non-goals

Closed #30 supplies the pinned adoption baseline; closed #97 introduced the shadow. There is no open blocking dependency. Open accessibility/account/content HUMAN follow-ups do not block this presentation rollback, and this issue must not absorb their scope.

Non-goals:

• reverting P0: Build a fully navigable Django review skeleton #97, Establish WCAG 2.2 AA patterns and verify every critical flow #65, Build deterministic SQLite test factories and a parallel-safe Django/Playwright harness #75, Make the main-site homepage the root route and namespace course discovery #95, Consolidate the adopted course account as the single website identity #100, Ship real public content on the final editorial route map #105, Expose safe site settings in Studio and the admin API #114, or Rename the copied cadmin package to Studio Courses without changing behavior #116 wholesale;
• changing Course/Cohort models, data, migrations, lifecycle, registrations, enrollments, scoring, or learner state;
• renaming or rolling back Studio Courses, restoring cadmin as a product namespace, or changing management authorization;
• replacing the empty-database public projection or duplicating its Course-family data inside copied CMP templates;
• redesigning the copied course cards/sections, creating a new design system, or broadly rewriting editorial page composition;
• removing canonical navigation, accessibility, security, route-compatibility, or development SEO safeguards;
• making request-time network calls or changing deployment infrastructure.

Process handoff

Implement from current main in an isolated worktree. The engineer implements and tests without committing. A separate tester verifies the exact candidate, runs focused Django/adoption/browser gates, and captures/reads the required screenshots. Product management accepts the user-visible rollback only after tester PASS. Then the engineer commits with Closes #128 unless the conditional deployed HUMAN gate is triggered; the orchestrator merges locally without a pull request, pushes, and hands the exact SHA to on-call.

[alexeygrigorev]

PM grooming report — implementation ready

Verdict: groomed as an unblocked P0 presentation rollback. needs grooming was removed and integration was added. No code, file, commit, branch, deployment, or other worktree was changed.

Repository/source findings

• I inspected pinned CMP commit 98a235283904b4ef9ad29e196298540756cf1bcc with git show, so unrelated dirty files in the source checkout did not enter the comparison.
• The pinned and adopted courses/templates/courses/course_list.html are byte-identical at SHA-256 26e391ffdd2c90b89a668c41118f4a8e43efd2b5dde015097f893aee707984ef.
• Current unified loader order is course_platform_templates/, project templates/, then app templates. The project file introduced by P0: Build a fully navigable Django review skeleton #97 therefore wins before the correct copied app template.
• Comparing every project template logical name with all 25 pinned courses/templates/** names found exactly one collision: courses/course_list.html.
• The empty-database templates/public/course_hub.html branch is separate and must remain; it does not collide with or justify overriding the database-backed CMP catalog.
• Existing shared shell changes are recorded CMP integrations for same-host navigation, account/Studio access, accessibility, security, canonical/noindex behavior, and local assets. They remain allowed; page-composition redesign does not.

Exact implementation handoff

1. Delete templates/courses/course_list.html; do not edit or re-copy the already-correct adopted template.
2. Add the 25-template fail-closed collision/resolution contract in core/tests/test_course_platform_adoption.py.
3. Cover database-backed copied rendering and the unchanged empty-database fallback in core/tests/test_homepage.py.
4. Document the no-shadow visual-source rule in _docs/adoption/course-platform/integration-patches.md.
5. Add deterministic desktop/mobile CMP-parity coverage in playwright_tests/test_course_design_parity.py and tighten deployed /courses assertions in playwright_tests/test_deployed_smoke.py.
6. Run the focused adoption/Django/readability/course workflow checks, core Playwright, copied CMP browser workflow, and inspect 1440×900 plus 390×844 screenshots under .tmp/screenshots/issue-128/.

No model/data/migration/view/URL/API/Studio namespace rollback belongs in this issue. The wider website continues to use the CMP-derived shared visual system; this fix removes the course-only composition fork.

[alexeygrigorev]

Software Engineer Report

Implemented the groomed CMP course-design rollback in isolated worktree .tmp/website-128-cmp-course-design on branch issue-128-cmp-course-design. The candidate is intentionally uncommitted and unpushed for independent tester review.

Behavior delivered

• Deleted the sole higher-precedence shadow, templates/courses/course_list.html.
• Left the adopted source template untouched and byte-identical to pinned CMP SHA-256 26e391ffdd2c90b89a668c41118f4a8e43efd2b5dde015097f893aee707984ef (91 readable lines).
• Added a fail-closed contract derived from the copy ledger: exactly 25 protected logical course-template names, no project-template collisions, and actual Django loader resolution to each recorded adopted destination.
• Added explicit homepage coverage for all three database states: no Course rows uses public/course_hub.html; visible rows use the copied CMP catalog and deterministic active/open-registration/archive order; a database with no visible courses keeps the source No active courses right now. empty state.
• Documented that future copied-course visual changes must be readable, in-place, hash-recorded overlays rather than higher-precedence redesigns.
• Added deterministic desktop/mobile browser parity for the copied catalog and representative detail page, including source composition, keyboard focus/Enter traversal, dark mode, 200% page-scale reflow, local assets, errors, and overflow.
• Tightened deployed /courses smoke assertions around copied-composition markers and absence of P0: Build a fully navigable Django review skeleton #97-only content.

Changed files

• Deleted templates/courses/course_list.html
• Updated _docs/adoption/course-platform/integration-patches.md
• Updated core/tests/test_course_platform_adoption.py
• Updated core/tests/test_homepage.py
• Added playwright_tests/test_course_design_parity.py
• Updated playwright_tests/test_deployed_smoke.py

No models, migrations, fixtures, imported content, views, routes, APIs, Studio mutations, shared shell/CSS, or deployment configuration changed.

Verification

PASS:

• DTC_TEST_RUN_ID=issue-128-final-focused DJANGO_SETTINGS_MODULE=website.settings.test uv run --frozen python manage.py test core.tests.test_course_platform_adoption core.tests.test_homepage --verbosity 1 — 20 passed.
• DTC_TEST_RUN_ID=issue-128-django DJANGO_SETTINGS_MODULE=website.settings.test uv run --frozen python manage.py test courses.tests content.tests.test_public_routes_and_seo content.tests.test_public_template_source core.tests.test_accessibility core.tests.test_course_platform_policy core.tests.test_course_platform_vendor_assets core.tests.test_homepage core.tests.test_course_platform_adoption --parallel --verbosity 1 — 538 passed.
• uv run --frozen python scripts/verify_course_platform_adoption.py --source /home/alexey/git/dtc-website/.tmp/cmp-source-98a2352 — 768 copied files and 4 target shims verified.
• DTC_TEST_RUN_ID=issue-128-browser DJANGO_SETTINGS_MODULE=website.settings.test uv run --frozen pytest playwright_tests/test_course_design_parity.py -v — 2 passed.
• DTC_TEST_RUN_ID=issue-128-playwright-core make test-playwright-core — 63 passed, 26 deselected.
• make lint
• make format-check — 429 files formatted.
• make typecheck — 331 source files checked.
• make migrations-check
• make database-portability-check
• make django-check
• make terminology-check
• make deployment-check
• make lock-check
• git diff --check

The copied live-style workflow was also exercised against a fresh .tmp/ SQLite database and synthetic local-only identities. Availability, admin authentication, provisioning, homework submission/scoring, project submission/review/scoring, course page, dashboard, leaderboard, and safe teardown checks passed. The focused run ended 24 passed, 2 failed, 1 skipped, 2 deselected because both account-settings assertions use wait_for_load_state("networkidle"); the server log proves /accounts/settings/, its local assets, timezone update, and preference response all completed, but Playwright never emitted networkidle. Subsequent course workflow tests passed. Teardown parked the isolated synthetic course after the existing impersonation-restoration helper lost the admin session. These are standalone-suite harness limitations outside this course-template candidate; no production or shared data was touched. The independent tester should still record its own verdict on the required gates.

Visual evidence inspected

Stored under .tmp/screenshots/issue-128/ with cmp-parity-attribution.json recording the pinned commit/hash, deterministic fixture, and viewports:

• course-catalog-cmp-desktop.png — 1440×1548 full page
• course-catalog-cmp-mobile.png — 390×1583 full page
• course-detail-cmp-desktop.png — 1440×900
• course-detail-cmp-mobile.png — 390×844
• course-detail-cmp-dark-desktop.png — 1440×900
• course-detail-cmp-dark-mobile.png — 390×844

All six were opened and inspected. They show the expected CMP catalog hierarchy (hero → active → open registration → archive), readable responsive cards, representative course detail in light/dark modes, local styling, and no clipping, horizontal overflow, debug/error page, or broken layout.

Frozen candidate fingerprint

Base: a22072842c4cad2bbbc8326c66356a7b66c35984

100644 1f794960e6e3d66ef620577fab8c6051cf77752a _docs/adoption/course-platform/integration-patches.md
100644 d9c06e3ba9ee084955c0b04546adf1bbd0f64132 core/tests/test_course_platform_adoption.py
100644 7c7eb6f53138d371ee7d8a5a16164dd97bbe08a1 core/tests/test_homepage.py
100644 c646b3ee706f3be8c041260b9045eb9111ddeffc playwright_tests/test_course_design_parity.py
100644 9aed06108394b916571cde8259a00b03b3317817 playwright_tests/test_deployed_smoke.py
deleted e055436f277ace37660854b6d85a8d904648df75 templates/courses/course_list.html

Aggregate SHA-256: 909edf1a755b766a24e5bd0689a3d4f0e7af52fb48ed88fdad92eb611c025bea.

[alexeygrigorev]

QA Review — TEST PASS

Verdict: PASS for the exact uncommitted candidate on branch issue-128-cmp-course-design, base/HEAD a22072842c4cad2bbbc8326c66356a7b66c35984.

I independently read the process, tester role, complete issue/PM/engineering reports, linked architecture/course/verification specifications, adoption provenance/overlay policy, exact diff, and pinned CMP source at 98a235283904b4ef9ad29e196298540756cf1bcc. I made no candidate edit, commit, push, merge, deployment, or remote mutation.

Acceptance matrix

Criterion	Result	Independent evidence
Sole project shadow absent; all 25 protected names collision-free	PASS	templates/courses/course_list.html is absent; ledger-derived project collision scan is empty; focused loader contract passes all 25 names.
Adopted course list remains readable and byte-identical to pinned CMP	PASS	Clean pinned checkout, pinned file, candidate file, and base-HEAD file all SHA-256 26e391ffdd2c90b89a668c41118f4a8e43efd2b5dde015097f893aee707984ef; source/candidate cmp succeeds; both are 91 line-broken lines.
Unified loader resolves every protected logical name to its recorded destination	PASS	Adoption contract loads all 25 under actual unified settings and compares each origin.name with its ledger destination.
Populated /courses uses copied CMP composition	PASS	Django and independent browser checks show pinned hero → Active courses → Open registration → Course archive order, two CMP role-link cards, source badges/controls/copy, and no #course-families-heading or No active cohort coursework right now..
No-row public projection and database-backed source empty state both remain correct	PASS	No Course rows render public/course_hub.html with current projection links; one hidden database row renders copied CMP No active courses right now.. Both were captured desktop/mobile/light/dark.
Shared shell/navigation/account/login/dark/accessibility/security/local assets/routes/Studio entry remain functional	PASS	Focused Django plus 63-test core Playwright pass; fresh browser checks cover canonical link, same-host nav, responsive Explore menu, Login, theme toggle, local-only styles/scripts, skip link, current Courses state, focus, and error-free requests/console.
Existing detail/enrollment/homework/project/peer-review/dashboard/leaderboard behavior does not regress	PASS	538 focused Django tests pass. Fresh copied live-style workflow proceeds through provisioning, impersonation state, homework submission/scoring, project submission/review/scoring, course/dashboard/leaderboard and safe cleanup; the two standalone account-settings waits are classified below.
Course-facing sources remain readable; no generated/minified replacement	PASS	Exact 91-line pinned course-list source retained; template-readability tests pass; diff deletes the redesign instead of modifying the adopted source.
1440×900 and 390×844 catalog parity, assets, errors and overflow	PASS	Populated copied catalog captured and inspected in light/dark at both viewports. Pinned source section hierarchy/cards/controls/spacing are intact; no clipping, horizontal overflow, broken asset, request/page/console error, debug page, or error page.
Representative detail, catalog-to-detail keyboard navigation, visible focus, dark mode, 200% reflow	PASS	Independent role-link Enter traversal reaches retained /<course-slug>/; skip/main/card focus assertions, visible outline, detail light/dark, and Chromium page-scale 2 reflow all pass at both viewports.
No model/migration/data/route/API/Studio/CSS/deployment redesign	PASS	Exact diff contains only the six groomed paths. No model, migration, fixture, view, URLconf, adopted course template, CSS/JS, API, Studio, or deployment configuration diff.

The screenshots are compared to the pinned CMP composition, not the removed override: candidate and pinned course-list template bytes are identical, and the browser assertions/evidence map directly to that source's hero, active/open/archive sections, source card markup, and source empty copy. Allowed shared-shell differences visible in evidence are the canonical DataTalks.Club navigation/header/footer, responsive Explore control, theme control, Login, version footer, local assets, and accessibility focus treatment; none changes the CMP page-specific hierarchy.

Commands and results

• DTC_TEST_RUN_ID=issue-128-tester-focused DJANGO_SETTINGS_MODULE=website.settings.test uv run --frozen python manage.py test core.tests.test_course_platform_adoption core.tests.test_homepage --verbosity 2 — 20 passed.
• DTC_TEST_RUN_ID=issue-128-tester-django DJANGO_SETTINGS_MODULE=website.settings.test uv run --frozen python manage.py test courses.tests content.tests.test_public_routes_and_seo content.tests.test_public_template_source core.tests.test_accessibility core.tests.test_course_platform_policy core.tests.test_course_platform_vendor_assets core.tests.test_homepage core.tests.test_course_platform_adoption --parallel --verbosity 1 — 538 passed.
• uv run --frozen python scripts/verify_course_platform_adoption.py --source /home/alexey/git/dtc-website/.tmp/cmp-source-98a2352 — 768 copied files and 4 target-owned shims verified.
• make compatibility-source-artifacts-check initially found its expected local pinned checkout absent. I used the documented project-local .tmp/legacy-compatibility-sources preparation/full-build command, then reran the gate — 6 source artifacts checked byte-for-byte, with no added tracked diff.
• make lint — pass; make format-check — 429 files already formatted; make typecheck — 331 source files, no issues.
• make migrations-check, make database-portability-check, make django-check, make terminology-check, make deployment-check, make lock-check, and git diff --check — all pass.
• DTC_TEST_RUN_ID=issue-128-tester-playwright-core make test-playwright-core — 63 passed, 26 deselected.
• Independent temporary browser evidence harness (removed after use), under isolated test settings — 2 viewport cases passed after correcting my scratch expected route from future /courses/<slug> to the retained CMP-compatible /<slug>/.
• Fresh local copied-CMP workflow, isolated .tmp SQLite and synthetic-only identities, selected live scenario files with -m 'not email' — 24 passed, 2 failed, 1 skipped, 2 deselected. The two failures are classified immediately below; all later course workflow scenarios passed. The synthetic database, credentials, server logs, scripts, bytecode, and cache were removed after diagnosis.

Standalone account-settings networkidle diagnosis

Both reported failures reproduced exactly in e2e/tests/test_02_enrollment.py, at AdminSession.open()'s unconditional wait_for_load_state("networkidle"):

• /accounts/settings/ returned 200 and independently showed the Account settings heading, complete settings form, three email toggles, and correct unavailable status.
• Passive /accounts/settings/timezone/ returned 200.
• With local Datamailer deliberately disabled, /accounts/settings/email-preferences/ returned the repository's explicitly tested safe 503. settings_toggles.js displayed Email preferences are temporarily unavailable. Try again later.
• Instrumentation showed Playwright emitted request and response 503 for that fetch but no requestfinished, no websocket existed, and networkidle timed out. A control fulfilling that endpoint with normal 200 JSON produced Email subscriptions loaded. and networkidle=true.
• None of e2e/browser.py, the account settings view/template/service, settings_toggles.js, or email-preference policy is changed by Restore the copied CMP design on course-facing pages #128.

Classification: pre-existing standalone-harness false negative / unrelated to this candidate, not a real course-template failure and not silently waived. The actual settings document and its designed safe-degradation state were verified, and every subsequent course workflow check passed. The teardown skip is the documented parked-hidden fallback after the existing impersonation-restoration helper loses the admin session; the isolated scratch database was removed.

Fresh visual evidence

All 16 PNGs below were opened and visually inspected under .tmp/screenshots/issue-128-tester/. They show the intended page—not a 404/debug/error page—with readable wrapping and no clipping/overflow. Light populated images intentionally retain the visible keyboard-focus evidence; dark images retain the focused theme control.

835dc050a3dbd4482869f34f1fa41a130bda1012c89061671db8f4a405e5881d  course-catalog-cmp-empty-dark-desktop.png
6b29ea0423ce03c3a7ed1378b4fb5a9974fbb090cf38c5c21a786b2fec8a2cf9  course-catalog-cmp-empty-dark-mobile.png
78c746c87cf33fafc97d1ce26eb1a1bdbb8bebd7cd542a9c88393f90817d8238  course-catalog-cmp-empty-light-desktop.png
de95dec4e17514924f8824b882616f360194b79c02799e5bd0e1d1476cfb2b57  course-catalog-cmp-empty-light-mobile.png
7567dc1891da2e2caf99a78afafd6a615d734123f88e21c7bb30c7f598985070  course-catalog-cmp-populated-dark-desktop.png
745b718ec754183ec1c364b27de3b2911929dad903204bfcd7d8a04e39e65ff5  course-catalog-cmp-populated-dark-mobile.png
e08a9568bda34ad815e03c11dc731592ab245231e725b1f403e4e852f5edb14e  course-catalog-cmp-populated-light-desktop.png
5bacde9dc2767e107e628c48a0b86cb205f28fd5b4d278a6b0773c3c6c293db3  course-catalog-cmp-populated-light-mobile.png
5daa3581932c8f288ffa834d0daf9482e24f898ddc3a84dc86f6f4baa3b9d127  course-catalog-public-fallback-dark-desktop.png
a150c90896db9fd51715db77c13fae92f194b70c56372501e60deade7c1c24b2  course-catalog-public-fallback-dark-mobile.png
55248f4f9e637d3b263e36bad0695b6b563d3d2bd8474f11a6acdc3675844b56  course-catalog-public-fallback-light-desktop.png
96389b37e74ba58679c1c85cfd4d8d2eda0f0e9cf8bb4b5c63f71ee992bef18a  course-catalog-public-fallback-light-mobile.png
c5f2329adae36a28e38b4d8d576a70529cb8dab47c661b8f248e45e1f44117c6  course-detail-cmp-dark-desktop.png
11e9467e50b4a729719d1fae14dafe3b6d6cb0a9b0caecd730a8526794e1d43b  course-detail-cmp-dark-mobile.png
73cb6a8374e5e7dc404528654896f2e41f4c2dfe884f99d00213db4967fe9534  course-detail-cmp-light-desktop.png
a6e406c949085b8f38a094f2edc94e674d3f535d6367c1385620d2feacf22a6d  course-detail-cmp-light-mobile.png

Sorted manifest serialization above plus final LF: SHA-256 622bc993d891bab1a022052847b5490b87ae3cfe33518f7e1057670b8cd57488. Attribution JSON: cmp-parity-attribution.json, SHA-256 a8b49059cc4bcad59ab1768c01e74999d8edaa621657139cf88a9d21c35142cc.

Candidate fingerprint and deployment-smoke safety

Initial and final per-path Git identities both exactly match the frozen engineering table:

100644 1f794960e6e3d66ef620577fab8c6051cf77752a _docs/adoption/course-platform/integration-patches.md
100644 d9c06e3ba9ee084955c0b04546adf1bbd0f64132 core/tests/test_course_platform_adoption.py
100644 7c7eb6f53138d371ee7d8a5a16164dd97bbe08a1 core/tests/test_homepage.py
100644 c646b3ee706f3be8c041260b9045eb9111ddeffc playwright_tests/test_course_design_parity.py
100644 9aed06108394b916571cde8259a00b03b3317817 playwright_tests/test_deployed_smoke.py
deleted e055436f277ace37660854b6d85a8d904648df75 templates/courses/course_list.html

The engineering report's aggregate 909edf1a... does not document its byte serialization and is not independently reproducible from the report. This is an evidence-format defect, not a candidate-identity mismatch: all six exact blobs match. My deterministic serialization is the six lines above in that order, single ASCII spaces, UTF-8, one LF after every line; initial and final SHA-256 are both dc9f11324fb5a2c7aefe92e8179ca14fcb5ff131cddeb9252bf3a53fd2467edb.

I inspected the tightened deployed smoke without running it remotely. It remains explicitly remote_readonly, requires exact safe development origin/release identity and project-local screenshot configuration, and performs only page navigation/GET requests plus assertions/screenshots (including the deliberate GET 404). It introduces no POST/PATCH/PUT/DELETE, form submit, login, deployment, or environment mutation. Remote deployment mutation was not run.

[alexeygrigorev]

Software Engineer Report — superseding 2ba92e5 handoff

This report supersedes the earlier a220728 engineering fingerprint. I reconciled the uncommitted #128 candidate onto authoritative pushed main at 2ba92e575ce894e30697c22391225a07efc525fc (the accepted #123 navigation guard) in the same isolated worktree and branch:

• worktree: .tmp/website-128-cmp-course-design
• branch: issue-128-cmp-course-design
• state: uncommitted and unpushed

The base advanced by a clean fast-forward. #123 changed only conftest.py, playwright_tests/test_network_guard.py, and test_support/tests/test_safety.py; none overlaps #128's six product paths. Reapplying #128 produced the exact same five file blobs and one deletion as the prior candidate. No semantic or visual source change was needed.

Candidate behavior and paths

• Deleted templates/courses/course_list.html, removing the only higher-precedence shadow.
• Kept courses/templates/courses/course_list.html untouched at pinned CMP SHA-256 26e391ffdd2c90b89a668c41118f4a8e43efd2b5dde015097f893aee707984ef and 91 readable lines.
• Updated _docs/adoption/course-platform/integration-patches.md with the no-shadow/readable-overlay contract.
• Updated core/tests/test_course_platform_adoption.py with the fail-closed 25-template collision/origin contract.
• Updated core/tests/test_homepage.py for no-database, visible database, and no-visible-course source-empty-state branches.
• Added playwright_tests/test_course_design_parity.py for deterministic desktop/mobile catalog/detail/light/dark/keyboard/zoom/local-asset parity.
• Updated playwright_tests/test_deployed_smoke.py with copied-composition and P0: Build a fully navigable Django review skeleton #97-absence markers.

No models, migrations, fixtures, imported content, views, routes, APIs, Studio mutations, shared shell/CSS, or deployment configuration changed.

Fresh verification on 2ba92e5

PASS:

• DTC_TEST_RUN_ID=issue-128-2ba-focused DJANGO_SETTINGS_MODULE=website.settings.test uv run --frozen python manage.py test core.tests.test_course_platform_adoption core.tests.test_homepage --verbosity 1 — 20 passed.
• DTC_TEST_RUN_ID=issue-128-2ba-django DJANGO_SETTINGS_MODULE=website.settings.test uv run --frozen python manage.py test courses.tests content.tests.test_public_routes_and_seo content.tests.test_public_template_source core.tests.test_accessibility core.tests.test_course_platform_policy core.tests.test_course_platform_vendor_assets core.tests.test_homepage core.tests.test_course_platform_adoption --parallel --verbosity 1 — 538 passed.
• uv run --frozen python scripts/verify_course_platform_adoption.py --source /home/alexey/git/dtc-website/.tmp/cmp-source-98a2352 — 768 copied files and 4 target shims verified.
• DTC_TEST_RUN_ID=issue-128-2ba-browser-rerun DJANGO_SETTINGS_MODULE=website.settings.test DJANGO_ALLOW_ASYNC_UNSAFE=true uv run --frozen pytest playwright_tests/test_course_design_parity.py -v — 2 passed with fresh desktop/mobile evidence.
• DTC_TEST_RUN_ID=issue-128-2ba-playwright-core-rerun make test-playwright-core — 96 passed, 26 deselected under Classify navigation-cancelled same-origin requests deterministically in Playwright #123, including both Restore the copied CMP design on course-facing pages #128 parity cases and all new navigation-guard cases.
• make lint format-check typecheck migrations-check database-portability-check django-check terminology-check deployment-check lock-check — all pass; 430 formatted, 331 typed, no migration drift, current OpenAPI/capability parity, no Django/deployment issues.
• git diff --check — pass.

The first full core invocation encountered one transient Chromium ERR_NETWORK_CHANGED teardown error in the pre-existing Studio revocation case. That exact case immediately passed in isolation, then the complete 96-test core matrix passed cleanly on rerun. No code was changed between those runs.

#123 / standalone E2E re-evaluation

I reran standalone CMP availability, provisioning, and enrollment against a fresh .tmp/ SQLite database and synthetic local-only identities: 9 passed, 2 failed. The two failures are the same existing AdminSession.open() wait_for_load_state("networkidle") timeouts on /accounts/settings/. Server evidence shows both HTML 200 responses, local preference 503 responses, and timezone 200 updates completed. This result is unchanged because standalone E2E selects e2e/pytest.ini, whose root is e2e/; it does not load the repository-root #123 conftest.py guard. Per scope, no unrelated harness was weakened or edited. Core Playwright—including the #128 course flow—is green under #123.

Fresh visual evidence

The focused browser rerun regenerated all six artifacts under .tmp/screenshots/issue-128/; cmp-parity-attribution.json still records pinned CMP commit 98a235283904b4ef9ad29e196298540756cf1bcc, the exact course-list digest, synthetic fixture, and viewports.

• catalog desktop 1440×1548 and mobile 390×1583
• detail light desktop 1440×900 and mobile 390×844
• detail dark desktop 1440×900 and mobile 390×844

I opened and inspected every regenerated image. The CMP hero → active → open-registration → archive composition, responsive cards, representative detail, dark mode, and shared shell remain unchanged; there is no clipping, overflow, debug/error page, or broken layout.

Reproducible frozen fingerprint

Serializer: UTF-8/ASCII text, LF line endings, literal tab separators, fixed path order shown below. Existing paths use mode plus git hash-object; the deleted path uses its base blob from HEAD:<path>.

serialize_issue128_candidate() {
  printf 'issue-128-candidate-manifest-v1\n'
  printf 'base\t%s\n' "$(git rev-parse HEAD)"
  for issue128_path in \
    _docs/adoption/course-platform/integration-patches.md \
    core/tests/test_course_platform_adoption.py \
    core/tests/test_homepage.py \
    playwright_tests/test_course_design_parity.py \
    playwright_tests/test_deployed_smoke.py \
    templates/courses/course_list.html; do
    if [ -f "$issue128_path" ]; then
      if [ -x "$issue128_path" ]; then issue128_mode=100755; else issue128_mode=100644; fi
      printf 'file\t%s\t%s\t%s\n' "$issue128_mode" "$(git hash-object "$issue128_path")" "$issue128_path"
    else
      printf 'deleted\t%s\t%s\n' "$(git rev-parse "HEAD:$issue128_path")" "$issue128_path"
    fi
  done
}
serialize_issue128_candidate | sha256sum

Serialized manifest:

issue-128-candidate-manifest-v1
base	2ba92e575ce894e30697c22391225a07efc525fc
file	100644	1f794960e6e3d66ef620577fab8c6051cf77752a	_docs/adoption/course-platform/integration-patches.md
file	100644	d9c06e3ba9ee084955c0b04546adf1bbd0f64132	core/tests/test_course_platform_adoption.py
file	100644	7c7eb6f53138d371ee7d8a5a16164dd97bbe08a1	core/tests/test_homepage.py
file	100644	c646b3ee706f3be8c041260b9045eb9111ddeffc	playwright_tests/test_course_design_parity.py
file	100644	9aed06108394b916571cde8259a00b03b3317817	playwright_tests/test_deployed_smoke.py
deleted	e055436f277ace37660854b6d85a8d904648df75	templates/courses/course_list.html

Aggregate SHA-256: cc875011fe7daa1344ae64a54b7801b74d5bf6074a6e34c1cd6198f472e7034c.