fix: Commit embedded formulas for go install @latest (#117)

* fix: Commit embedded formulas for go install @latest

The internal/formula/formulas/ directory was gitignored, causing
`go install github.com/steveyegge/gastown/cmd/gt@latest` to fail with:

  pattern formulas/*.formula.json: no matching files found

The go:embed directive requires these files at build time, but
go install @latest doesn't run go:generate. By committing the
generated formulas, users can install directly without cloning.

Maintainers should run `go generate ./...` after modifying
.beads/formulas/ to keep the embedded copy in sync.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* ci: Add check for committed embedded formulas

Adds a new CI job that:
1. Builds without running go:generate (catches missing formulas)
2. Verifies committed formulas match .beads/formulas/ source

Also removes redundant go:generate steps from other jobs since
formulas are now committed.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* chore: exclude towers-of-hanoi test formulas from embed

These are durability stress test fixtures (pre-computed move sequences),
not production formulas users need. Excluding them reduces embedded
content by ~10K lines.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: gus <steve.yegge@gmail.com>

.github/workflows/ci.yml

@@ -33,6 +33,36 @@ jobs:
           fi
           echo "No .beads/issues.jsonl changes detected"
 
+  # Verify committed formulas allow build without go:generate
+  # This catches issues where go install @latest would fail
+  check-embedded-formulas:
+    name: Check embedded formulas
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.24'
+
+      - name: Build without go:generate
+        run: |
+          # This must succeed with committed formulas only
+          # If this fails, run: go generate ./... && git add -A && git commit
+          go build -v ./cmd/gt
+
+      - name: Verify formulas are in sync
+        run: |
+          # Regenerate and check for differences
+          go generate ./internal/formula/...
+          if ! git diff --exit-code internal/formula/formulas/; then
+            echo ""
+            echo "ERROR: Committed formulas are out of sync with .beads/formulas/"
+            echo "Run: go generate ./... && git add -A && git commit"
+            exit 1
+          fi
+
   test:
     name: Test
     runs-on: ubuntu-latest
@@ -49,9 +79,6 @@ jobs:
           git config --global user.name "CI Bot"
           git config --global user.email "ci@gastown.test"
 
-      - name: Generate embedded files
-        run: go generate ./internal/formula/...
-
       - name: Build
         run: go build -v ./cmd/gt
 
@@ -69,9 +96,6 @@ jobs:
         with:
           go-version: '1.24'
 
-      - name: Generate embedded files
-        run: go generate ./internal/formula/...
-
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v9
         with:
@@ -97,9 +121,6 @@ jobs:
       - name: Install beads (bd)
         run: go install github.com/steveyegge/beads/cmd/bd@latest
 
-      - name: Generate embedded files
-        run: go generate ./internal/formula/...
-
       - name: Build gt
         run: go build -v -o gt ./cmd/gt