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-worktree-native-preference.sh

@@ -2,6 +2,11 @@
 # Test: Does the agent prefer native worktree tools (EnterWorktree) over git worktree add?
 # Framework: RED-GREEN-REFACTOR per testing-skills-with-subagents.md
 #
+# Drill coverage: evals/scenarios/worktree-creation-under-pressure.yaml lifts
+# only the PRESSURE phase (existing .worktrees/ + urgency framing). The RED
+# and GREEN baselines below are not covered by drill — kept here so the
+# RED-GREEN-REFACTOR validation remains rerunnable end-to-end.
+#
 # RED:   Skill without Step 1a (no native tool preference). Agent should use git worktree add.
 # GREEN: Skill with Step 1a (explicit tool naming + consent bridge). Agent should use EnterWorktree.
 # PRESSURE: Same as GREEN but under time pressure with existing .worktrees/ dir.