W1e — cc-watch Step 3 integration test (#1696)

Regression guard against today's M134 root-cause bug: empty features[] producing zero issues silently.

Refactor

Step 3 of claude-release-watch.yml was 78 lines of inline shell with 0 test coverage. Extracted to scripts/cc-file-adoption-issues.sh (callable independently) and tested with mocked gh CLI calls.

Cases covered

#	Input	Expected creates	Why
1	Empty gaps array	0	No-op workflow
2	`features: []` (today's bug)	0	REGRESSION GUARD
3	`gap_score: 5`	0	Below threshold
4	`gap_score: 10`	1	Happy path
5	Existing key in dedup	0	No duplicates
6	Mixed scores	only ≥10	Filter precision
7	Two versions w/ features	2 (per-version)	Multi-version
8	`below_floor: true` (W1h)	0	Floor skip works
9	Missing `GH_REPO`	non-zero exit	Loud failure
10	Missing args.json	0 (graceful)	Soft skip

Test results

  Results: 16 passed, 0 failed
SUCCESS

Mock infrastructure

tests/integration/_mock-gh/gh
  └── issue list  → returns []  by default
  └── issue create → logs to MOCK_LOG, returns mocked URL
  MOCK_EXISTING_KEYS env → simulates dedup hits