tests: annotate three kept bash tests with drill coverage notes

- test-worktree-native-preference.sh: drill covers PRESSURE phase only;
  RED + GREEN baselines have no drill counterpart and are kept so
  the RED-GREEN-REFACTOR validation remains rerunnable end-to-end.
- test-subagent-driven-development-integration.sh: drill covers the
  YAGNI subset (forbidden exports + reviewer-as-gate). Bash adds
  >=3 commits, >=2 subagent dispatches, TodoWrite usage, test file
  existence check, and token-budget telemetry. Kept until drill
  scenario covers those or they are retired.
- test-subagent-driven-development.sh: tests agent's ability to
  *describe* SDD (string matches against expected keywords). Drill
  scenarios test behavior, not description-recall. Kept by design.

Subagent verification recorded in commit messages of subsequent
deletions; gap analyses driving these annotations are also in the
verification subagent reports for the gating sweep.

tests/claude-code/test-subagent-driven-development-integration.sh

@@ -1,6 +1,17 @@
 #!/usr/bin/env bash
 # Integration Test: subagent-driven-development workflow
 # Actually executes a plan and verifies the new workflow behaviors
+#
+# Drill coverage: evals/scenarios/sdd-rejects-extra-features.yaml covers the
+# YAGNI enforcement subset (forbidden exports + reviewer-as-gate semantics)
+# and is stricter on that axis. This bash test additionally asserts:
+#   - >=3 git commits (initial + per-task commits, exercising SDD's
+#     commit-per-task workflow shape)
+#   - >=2 Agent/Task subagent dispatches (drill only asserts >=1)
+#   - TodoWrite usage (drill makes no assertion)
+#   - test/math.test.js exists (drill relies on `npm test` succeeding)
+#   - analyze-token-usage.py token-budget telemetry
+# Kept until those assertions are added to drill or explicitly retired.
 set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"