fix(cli): wait for the task tree's graceful shutdown on ctrl-c

[fengmk2]

Closes #2036

Builds on #2065 by @forehalo: this branch carries both of its commits as-is (the execute_with_terminal_guard integration with terminal-state restore, applied to both delegation call sites), with follow-up commits adjusting the signal handling on top.

Background: Ctrl+C is delivered by the terminal to the whole foreground process group, and the delegating global vp is the PTY session leader. It used to die of SIGINT within milliseconds, handing the terminal back to the shell (and SIGHUP'ing the session) while the task tree (vite dev server, managed node) was still shutting down. The dying tree's late terminal writes and mode restores then raced the shell's prompt probes (fish sends OSC 11, CSI 6n, and DA1 at every prompt draw), turning the terminal's replies into the garbage input from the issue.

Adjustments on top of #2065:

• Interrupt swallowing moves from the guard's SIG_IGN sigaction into the wait loop as a signal handler. SIG_IGN survives exec into the entire child tree, so any task without its own SIGINT handler would become uninterruptible (node launders inherited dispositions at startup, which masks this for the delegation path today, but the guard is shared code and the binding call site spawns other children). A handler resets to default on exec and leaves children untouched, and also works when stdin is not a terminal, where the guard never installs.
• A second Ctrl+C force-kills the child, so a task that ignores the first interrupt cannot make vp unstoppable. Verified against the SIG_IGN variant: a stuck task left vp hanging until externally killed.
• Children killed by a signal now exit with the conventional 128 + signal code (130 for SIGINT, 137 for the force-kill) instead of a generic 1.
• Windows gets the same swallow-and-escalate loop via the console Ctrl+C handler.

The run_ctrlc_teardown snapshot from #2069 flips to task completed its graceful shutdown and now guards the waiting behavior; a second case pins the escalation (task ignoring the interrupt, force-killed by the second Ctrl+C, exit 137). Verified end to end by driving real fish 4.8 in a scripted PTY: the stray escape sequences no longer appear on the prompt after killing vp run dev.

Known residual edge (follow-up, vite-task side): a shell-wrapped script line whose intermediate shell dies of SIGINT can still orphan grandchildren, since vite_task waits only for its direct child; waiting on the task's process group would close that.

[fengmk2]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• fix(cli): wait for the task tree's graceful shutdown on ctrl-c #2070 👈 (View in Graphite)
• test(snapshot): reproduce vp run ctrl-c tearing tasks down mid-shutdown #2069
• main

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[github-actions]

Registry bridge build (060115f)

This commit build is published to the registry bridge, which serves these as ordinary npm versions (every other package proxies to npmjs):

Package	Version
vite-plus	0.0.0-commit.060115f340ebbeed547dd5eff887b0d23f8baee4
@voidzero-dev/vite-plus-core	0.0.0-commit.060115f340ebbeed547dd5eff887b0d23f8baee4

Install the Vite+ CLI built from this commit, then migrate a project:

# macOS / Linux
curl -fsSL https://vite.plus | VP_PR_VERSION=2070 bash

# Windows (PowerShell)
$env:VP_PR_VERSION="2070"; irm https://vite.plus/ps1 | iex

After installing, upgrade the current project's vite-plus to this test build with:

vp migrate

Or point your package manager at the bridge registry https://registry-bridge.viteplus.dev/:

Package manager	Registry config
npm / pnpm / Bun	.npmrc: registry=https://registry-bridge.viteplus.dev/
Yarn (v2+)	.yarnrc.yml: npmRegistryServer: "https://registry-bridge.viteplus.dev/"

Then pin the build (vite aliases to vite-plus-core; pnpm can use a catalog, npm an overrides entry):

{
  "devDependencies": {
    "vite-plus": "0.0.0-commit.060115f340ebbeed547dd5eff887b0d23f8baee4",
    "vite": "npm:@voidzero-dev/vite-plus-core@0.0.0-commit.060115f340ebbeed547dd5eff887b0d23f8baee4"
  }
}

[github-actions]

🐳 Docker preview image

Built from this PR's registry bridge build:

Image	Compressed size
ghcr.io/voidzero-dev/vite-plus:pr-2070	240MB

# remove any stale local copy from a previous run, then pull fresh
docker rmi ghcr.io/voidzero-dev/vite-plus:pr-2070 2>/dev/null; docker pull ghcr.io/voidzero-dev/vite-plus:pr-2070

Quick check:

docker run --rm ghcr.io/voidzero-dev/vite-plus:pr-2070 vp --version

See docs/guide/docker.md for usage.

[fengmk2]

Consolidated into #2065: the fix commits (including the adjustments from this PR) have been pushed onto that branch so the fix lands under the original contributor's PR.