refactor: drop 12 runtimes, keep Claude, Codex, OpenCode, Cursor, ZCode, Antigravity

Removes kilo, kimi, kimi-code, copilot, windsurf, augment, trae, qwen, hermes,
cline, codebuddy and pi end to end: capability descriptors, installer branches
and converters (bin/install.js 14.9k -> 11.2k lines), TypeScript converters,
hook surfaces and runtime homes, review lanes qwen/kimi-code, the two pi
migrations, Kimi payload normalization in the hook guards, dead hostBehaviors
vocabulary, launcher home probes, fixtures, runtime-specific tests and the
prose that presented them as supported.

Installer output for the six kept runtimes is byte-identical to before the
prune. The Kimi tool-vocabulary tests in workflow-guard, read-guard and
read-injection-scanner are left in place pending a decision.

commands/msd/onboard.md

@@ -12,10 +12,6 @@ allowed-tools:
   - AskUserQuestion
 requires: [config, new-project, map-codebase, ingest-docs, manager]
 ---
-<runtime_note>
-**Copilot (VS Code):** Use `vscode_askquestions` wherever this workflow calls `AskUserQuestion`. They are equivalent — `vscode_askquestions` is the VS Code Copilot implementation of the same interactive question API.
-</runtime_note>
-
 <objective>
 Guide brownfield onboarding for an existing codebase by routing through the existing MSD primitives in the safe order: codebase map → docs ingest → project initialization → onboarding summary.