fix(#2089): wire adapter into install path + address all review findings

MEDIUM fixes (code review):
- Wire resolveManagedHookEvents + resolveHookScripts + buildHookBusEntries
  from imperative-hook-bus.cts into writeCursorHooksJson — the install path
  is now truly descriptor-driven (reads hostBehaviors.managedHookEvents),
  not a hardcoded constant that happens to match the descriptor. bin/install.js
  passes the descriptor list via opts.managedHookEvents.
- buildHookBusEntries is now consumed (was dead code); entry-building is no
  longer duplicated inline.
- Remove try/finally from cursor-hook-bus-upgrade.test.cjs test bodies
  (violated CONTRIBUTING.md L342; redundant with t.after cleanup).

LOW fixes:
- Remove dead require('fs')/require('path') from gsd-cursor-pre-tool.js
- Fix resolveManagedHookEvents docstring (all-invalid fallback behavior)
- Add src/runtime-hooks-surface.cts to the AC2 source-guard file list

Security review: no CRITICAL/HIGH/MEDIUM findings (3 LOW are pre-existing
#777 baseline patterns, not regressions).

src/host-integration-adapters/imperative-hook-bus.cts

@@ -73,7 +73,9 @@ export const GSD_HOOK_MARKER = 'gsd-managed';
  * (backward-compat for descriptors predating #2089).
  *
  * Pure: no I/O, never throws. Unknown event names are silently filtered
- * (fail-closed — an unrecognized event is never registered).
+ * (fail-closed — an unrecognized event is never registered). Falls back to
+ * the full CURSOR_HOOK_EVENTS set when the descriptor is absent or all entries
+ * are unrecognized (ensures the portable-event floor is always covered).
  *
  * @param managedHookEvents - the descriptor's `hostBehaviors.managedHookEvents` array
  * @returns a deduplicated, validated array of event names