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/msd-check-update-worker.js

@@ -101,16 +101,16 @@ try {
 // Check for stale hooks — compare hook version headers against installed VERSION
 // Since #3023 the bundle directory name is resolved from __dirname (this
 // worker is staged INSIDE the bundle), not assumed to be configDir/hooks —
-// the directory name is runtime-descriptor-driven (e.g. `msd-hooks/` for pi).
+// the directory name is runtime-descriptor-driven (hostBehaviors.sharedHooksDirName).
 // Only check hooks that MSD currently ships — orphaned files from removed features
 // (e.g., msd-intel-*.js) must be ignored to avoid permanent stale warnings (#1750)
 // MANAGED_HOOKS is imported from ./managed-hooks-registry.cjs above.
 
 const staleHooks = [];
 if (configDir) {
-  // #3023: the bundle's directory name is runtime-descriptor-driven (pi stages
-  // it as `msd-hooks/`), so deriving it as `<configDir>/hooks` silently scanned
-  // nothing there. This worker is staged INSIDE the bundle, so __dirname is the
+  // #3023: the bundle's directory name is runtime-descriptor-driven
+  // (hostBehaviors.sharedHooksDirName), so deriving it as `<configDir>/hooks`
+  // could silently scan nothing there. This worker is staged INSIDE the bundle, so __dirname is the
   // bundle directory by construction — name-agnostic and one fewer assumption.
   const hooksDir = __dirname;
   try {