* fix: read resources from dist/ to prevent branch-drift in npm-link setups
initResources() reads extensions, prompts, skills, and agents from
src/resources/ — which points into the live working tree when gsd is
installed via npm link. Switching branches in the gsd repo changes
src/resources/ for ALL projects using gsd, causing stale or broken
extensions to be synced to ~/.gsd/agent/ on next launch.
Fix: the build step now copies src/resources/ to dist/resources/.
At runtime, resource-loader.ts and loader.ts prefer dist/resources/
(stable, set at build time) over src/resources/ (live working tree).
Fallback to src/resources/ is preserved for setups without a build.
Also adds npm run dev watch-resources watcher that syncs src/resources/
to dist/resources/ on file changes, running alongside tsc --watch.
* fix: cache prompt templates per session to prevent cross-session invalidation
When two gsd sessions run concurrently, the second session's
initResources() overwrites ~/.gsd/agent/ templates on disk. The first
session then reads a newer template that expects variables its in-memory
code doesn't know about, causing 'template declares {{X}} but no value
was provided' crashes that hang auto-mode indefinitely.
Fix: cache each template on first read. A running session uses the
template versions from when it first loaded them, immune to later
disk overwrites by other sessions.
