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.

docs/how-to/interpret-install-shadow-warnings.md

@@ -62,7 +62,7 @@ Absence of a shadow warning is not always proof that nothing is shadowed. MSD Co
 
 - Only one scope is installed for that runtime.
 - Both scopes resolve to the *same* config directory (for example, `--config-dir` pointed both installs at the same place) — this is one physical install, not two.
-- The runtime's global scope installs no trigger-bearing artifact kind at all (windsurf's global install is `agents`, which is never invoked by a `/msd-<name>` trigger) — there is nothing for the local scope to collide with.
+- The runtime's global scope installs no trigger-bearing artifact kind at all (e.g. a runtime whose global install is `agents` only, which is never invoked by a `/msd-<name>` trigger) — there is nothing for the local scope to collide with.
 - The other scope's manifest exists but declares zero files (an empty or partial install at that scope).
 
 **Could not look (degraded, not verified)** — the check itself could not run, and its silence carries no claim either way: