feat(plugin): add Dameng DM8 support

[sophiathedev]

Adds first-class Dameng DM8 support as a downloadable macOS database-driver plugin.

Preview

What you get

• Connect with the dm:// URL scheme and browse or switch schemas without installing a local DM client.
• Browse tables, views, columns, indexes, and foreign keys; run queries, edit rows, use transactions, and generate DDL.
• Get DM8-specific statements, functions, data types, schemas, tables, views, and columns while typing.
• Inspect generated table metadata and render native DM8 EXPLAIN output in TablePro's visual plan view.
• Build and publish the plugin for both Apple Silicon and Intel Macs.

Driver architecture and safety

The plugin uses Swift for TablePro integration, a documented C ABI for ownership boundaries, and a Rust native-wire bridge. The bridge vendors a pinned MIT-licensed rust-dameng snapshot with compatibility fixes for multi-column results, DECIMAL values, empty result sets, bounded message reads, LOB limits, and DM8's text EXPLAIN response.

Parameter substitution is SQL-state aware, escapes text values, and encodes binary values with HEXTORAW. Native panics are contained at the C boundary, response and LOB allocations are capped, row limits stop after the requested cap plus a truncation sentinel, and unrecoverable protocol failures close the connection.

Native TLS is not available yet; the documentation recommends SSH, SOCKS, or Cloudflare tunnels for untrusted networks. Native binary and off-row LOB reads remain documented limitations.

Tests

• DamengDriverTests.xctest against DM8 in OrbStack: 6 tests passed, including schema/table/view metadata, empty foreign-key results, Unicode and binary values, row caps, EXPLAIN, transactions, invalid credentials, hostile inputs, and cleanup.
• Rust bridge and vendored protocol/type suites: 192 tests passed; the ignored OrbStack bridge workflow also passed separately.
• Apple Silicon and Intel plugin builds: BUILD SUCCEEDED.
• Focused TablePro registry, database-type, auto-limit, statement-classifier, parameter-binder, and plan-parser suites: TEST SUCCEEDED.
• swift test --package-path Packages/TableProCore: 181 tests passed.
• swiftlint lint --strict: clean.

The aggregate TablePro test run reached unrelated existing failures and then stalled in MCPBridgeIntegrationTests.BridgeHarness.startReader(); all DM8 and changed-area suites pass. SwiftFormat 0.62.1 cannot read the repository's existing legacy --ifdefindent option.

Closes #1671
Closes #2010
Related to #2003