perf(ci): cache dependencies, Jest transforms, and TSC build info + remove duplicate docs:sync (#202)

* perf(ci): cache node_modules and agent .venv in build workflow

Adds actions/cache for node_modules (keyed on yarn.lock) and
agent/.venv (keyed on uv.lock). Includes timing instrumentation
via SECONDS and ::notice annotations to measure cache-hit vs cold
install performance across runs.

Expected: Install step drops from ~75s (cold) to ~5s (cache hit).

Refs #201

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* perf(ci): add Jest transform cache with stable cacheDirectory

Sets cacheDirectory to <rootDir>/.jest-cache (off tmpfs, persists
locally) and caches it in CI via actions/cache keyed on yarn.lock +
commit SHA with restore-keys fallback for cross-branch reuse.

Expected: test step drops from ~90s to ~40-50s on cache hit since
ts-jest skips re-transpiling unchanged source files.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* ci: trigger cache-warm run (empty commit)

No-op commit to trigger a second CI run where caches are warm.
Compare Install/Build timing annotations with the prior cold run.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* ci: trigger third run — all caches should be warm

Previous warm run missed jest cache (cold run was still saving).
Now all three caches are fully saved. This run validates full hit.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* perf(ci): cache TypeScript build info and remove duplicate docs:sync

- Caches cdk/tsconfig.tsbuildinfo and cli/tsconfig.tsbuildinfo keyed
  on source file hashes with restore-keys fallback. Enables tsc
  incremental compilation to skip unchanged files (~10-20s savings).

- Removes redundant `//docs:sync` from root tasks.build — already
  runs as a dependency of `//docs:build` (~5s wasted per build).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(ci): upgrade actions/cache v4.2.3 → v5.0.5 (Node 24 compatible)

v4.2.3 runs on Node 20 which is deprecated and will be forced to
Node 24 starting June 2, 2026.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix(ci): include tsconfig files in TSC cache key

Tightens the cache key to invalidate when tsconfig.json or
tsconfig.dev.json change, not just source files. Prevents stale
.tsbuildinfo from surviving config changes.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* perf(ci): add explicit incremental: true to CDK and CLI tsconfigs

Ensures tsc generates .tsbuildinfo for incremental compilation.
While `tsc --build` implies incremental, being explicit guarantees
the behavior regardless of invocation mode.

Verified locally:
  CDK compile: 16s cold → 0.16s incremental (99% faster)
  CLI compile: 4s cold → 0.14s incremental (97% faster)

Also adds *.tsbuildinfo to .gitignore.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: bgagent <345885+scottschreckengaust@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: scottschreckengaust

.github/workflows/build.yml

@@ -65,6 +65,7 @@
     "node": ">= 20.x <= 24.x"
   },
   "jest": {
+    "cacheDirectory": "<rootDir>/.jest-cache",
     "coverageProvider": "v8",
     "testMatch": [
       "<rootDir>/@(src|test)/**/*(*.)@(spec|test).ts?(x)",

.gitignore

@@ -1,5 +1,6 @@
 {
   "compilerOptions": {
+    "incremental": true,
     "rootDir": "src",
     "outDir": "lib",
     "alwaysStrict": true,

cdk/package.json

@@ -160,7 +160,6 @@ run = [
   "MISE_EXPERIMENTAL=1 mise //cdk:build",
   "MISE_EXPERIMENTAL=1 mise //cli:build",
   "MISE_EXPERIMENTAL=1 mise //docs:build",
-  "MISE_EXPERIMENTAL=1 mise //docs:sync",
 ]
 
 [tasks.default]