Cover the agent-callable tools, the tunnel supervisor and the operator commands

[garethx]

Closes #2.

Coverage was 67% overall, but as #2 argued, the distribution was the problem: the surface an LLM drives unsupervised against a live project was the least tested part of the codebase, and tools.py had no test file at all.

Module	Before	After
tools.py	29% (no test file)	100%
cli.py	34%	85%
tunnel.py	41%	91%
dashboard/plugin_api.py	64%	83%
overall	67%	86%

88 new tests. No production code changes — the only non-test edit is adding .coverage to .gitignore.

What is actually asserted

The emphasis is on what decides which resource gets mutated, rather than on return-value shape.

• The pause ceiling — MAX_PAUSE_MINUTES is the only thing between a confused agent and an indefinitely paused connection. Every way a model can produce a bad number is covered: "10", -30, [], None, absent, over-cap. Plus that the minutes the tool reports are the minutes it actually scheduled, since the model plans against that number.
• Pause → auto-resume, end to end. The tool writes a deadline to the ledger; adapter._resume_due_connections honours it. Covered separately, both halves pass while disagreeing about the ledger path or the row shape — and a deadline written where the adapter never looks is indistinguishable from the feature silently not existing.
• The dashboard's ownership check on its refusal path. _require_own_connection is what stops this tab pausing somebody else's production traffic, and the endpoint is reachable whether or not the tab renders a button for it. Also that every configured route is consulted, not just the first.
• The tunnel's backoff reset rule, which Increase test coverage, starting with the agent-callable tools #2 correctly flagged as easy to get backwards, along with terminate-then-kill on shutdown and the hookdeck ci opt-in.
• doctor, including the check for a retry rule narrower than what the adapter emits — the silent-data-loss case.

Verification

The three safety-critical assertions were mutation-checked rather than trusted to the coverage number. Each of these fails the suite:

Mutation	Caught by
Remove the pause ceiling	3 tests
Disable the ownership check	2 tests
Invert the backoff reset rule	2 tests

One test initially passed for the wrong reason and is worth calling out: RunLedger.__init__ calls mkdir(parents=True), so an "unwritable path" was being silently created. It now patches RunLedger to raise, and asserts both that the connection is still paused and that the failure is logged — a pause recorded nowhere is recoverable, a pause that fails silently is not.

Merge order

This should land after #3. It is based on main and adds no new merge conflicts — test-merging this branch against #3 produces exactly the same four conflicts (README.md, adapter.py, cli.py, test_adapter.py) that #3 already has against main, because #3 is four commits behind. tests/test_cli.py and tests/test_dashboard_api.py auto-merge cleanly.

The second commit here removes the couplings to #3 that would otherwise have caused spurious failures: the doctor tests no longer pin HOOKDECK_API_KEY by name (either spelling satisfies them), no longer assert on wording that #3's API-key message changes, and clear both env-var spellings so a developer's shell cannot make a check pass for the wrong reason.

Left alone, per #2's own ordering: adapter.py (72%) and dashboard/dist/index.js.