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.

eslint.config.mjs

@@ -240,7 +240,6 @@ export default tseslint.config(
       'msd-core/bin/lib/installer-migrations/007-retire-config-root-commonjs-marker.cjs',
       // 009 also imports node builtins (fs, path) like 007, so tsc emits the
       // same `__importDefault` helper. ADR-457: the linted source is the .cts.
-      'msd-core/bin/lib/installer-migrations/009-pi-retire-reserved-hooks-dir.cjs',
       // 010 also imports node builtins (fs, path) like 007/009, so tsc emits
       // the same `__importDefault` helper. ADR-457: the linted source is the .cts.
       'msd-core/bin/lib/installer-migrations/010-antigravity-retire-confighome-artifacts.cjs',
@@ -525,10 +524,8 @@ export default tseslint.config(
       'scripts/**/*.cjs',
       'eslint-rules/**/*.cjs',
       'bin/lib/**/*.cjs',
-      'pi/**/*.cjs',
       'examples/**/*.cjs',
       'vscode/*.js',
-      '.kilo/plugins/*.js',
       '.opencode/plugins/*.js',
     ],
     plugins: {
@@ -688,7 +685,6 @@ export default tseslint.config(
     ignores: [
       'src/installer-migrations/003-rename-get-shit-done-to-msd-core.cts',
       'src/installer-migrations/004-prune-stale-pristine-snapshots.cts',
-      'src/installer-migrations/009-pi-retire-reserved-hooks-dir.cts',
       'src/installer-migrations/010-antigravity-retire-confighome-artifacts.cts',
     ],
     plugins: {