SMITH-023 Integrate extension management and contribution mapping

[webfish0]

Outcome

Compatible Code OSS extensions install, activate, and contribute terminal UI.

Scope

• Reuse extension scanning, install, enable/disable, and host placement.
• Map commands, configuration, keybindings, tree views, status items, SCM, tasks, tests, debug, diagnostics, and themes.
• Isolate extension-host crashes and activation hangs.
• Gate project-local extension execution with workspace trust.

Acceptance criteria

• T-014 and T-023 pass for the representative extension set.

Requirements: FR-012, FR-014, US-006, US-009

Source: backlog.md SMITH-023.

[webfish0]

MVP-4 language and extension compatibility slice landed and was verified on clean commit b1e07b5.

Evidence summary:

• Command: npm run verify:mvp
• Result: passed
• T-014: passed — native extension contributions classify to terminal-safe surfaces
• T-014-language: passed — completion, diagnostics, hover, and code action view models expose terminal-safe data
• T-015: passed — webview/custom editor/notebook graphical surfaces are explicitly unsupported
• T-016-subset: passed — extension configuration, keybindings, and walkthrough textual fallback remain visible to configuration surfaces
• Evidence path from local/CI run: test-evidence/mvp-4-language-extensions/

Known limitation: this slice validates manifest classification and terminal-safe language-feature view models. Live Code OSS extension-host activation and real extension execution remain pending before closing full extension compatibility tasks.