fix(ci,tests): pin bd to v0.47.1 and fix hash-like test suffixes

Pin bd (beads CLI) to v0.47.1 in CI workflows and fix test agent IDs
that trigger bd's isLikelyHash() prefix extraction logic.

Changes:
- Pin bd to v0.47.1 in ci.yml and integration.yml (v0.47.2 has routing
  defaults that cause prefix mismatch errors)
- Fix TestCloseAndClearAgentBead_FieldClearing: change agent IDs from
  `test-testrig-polecat-0` to `test-testrig-polecat-all_fields_populated`
- Fix TestCloseAndClearAgentBead_ReasonVariations: change agent IDs from
  `test-testrig-polecat-reason0` to `test-testrig-polecat-empty_reason`

Root cause: bd v0.47.1's isLikelyHash() treats suffixes of 3-8 chars
(with digits for 4+ chars) as potential git hashes. Patterns like `-0`
(single digit) and `-reason0` (7 chars with digit) caused bd to extract
the wrong prefix from agent IDs.

Using test names as suffixes (e.g., `all_fields_populated`) avoids this
because they're all >8 characters and won't trigger hash detection.

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

.github/workflows/ci.yml

@@ -235,7 +235,8 @@ jobs:
           git config --global user.email "ci@gastown.test"
 
       - name: Install beads (bd)
-        run: go install github.com/steveyegge/beads/cmd/bd@latest
+        # Pin to v0.47.1 - v0.47.2 has routing defaults that cause prefix mismatch errors
+        run: go install github.com/steveyegge/beads/cmd/bd@v0.47.1
 
       - name: Build gt
         run: go build -v -o gt ./cmd/gt

.github/workflows/integration.yml

@@ -30,7 +30,8 @@ jobs:
           git config --global user.email "ci@gastown.test"
 
       - name: Install beads (bd)
-        run: go install github.com/steveyegge/beads/cmd/bd@latest
+        # Pin to v0.47.1 - v0.47.2 has routing defaults that cause prefix mismatch errors
+        run: go install github.com/steveyegge/beads/cmd/bd@v0.47.1
 
       - name: Add to PATH
         run: echo "$(go env GOPATH)/bin" >> $GITHUB_PATH