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.

hooks/lib/git-probe.js

@@ -3,8 +3,8 @@
 // distinguishing a GENUINE negative answer (git ran and said "no") from
 // "could not determine" (timeout / spawn failure / signal kill) — #3911.
 //
-// Proven defect: hooks/msd-worktree-path-guard.js, hooks/msd-workflow-guard.js,
-// and hooks/msd-windsurf-pre-write.js each treat spawnSync(git, ..., {timeout})
+// Proven defect: hooks/msd-worktree-path-guard.js and hooks/msd-workflow-guard.js
+// each treat spawnSync(git, ..., {timeout})
 // returning a non-zero/empty result as "not applicable" and allow silently.
 // A macOS CI run showed three deny cases land at 2084ms/2112ms/2177ms — just
 // past the 2000ms budget — each returning exit 0 with EMPTY stdout AND EMPTY