## Summary
Expands the `/.well-known/healthcheck.json` endpoint with runtime statistics, giving operators visibility into server load and usage patterns.
closes#74
## New healthcheck fields
| Field | Source | Description |
|-------|--------|-------------|
| `sessions` | DB | Current active session count |
| `clients` | DB | Current connected client count |
| `queuedLines` | DB | Total entries in client output queues |
| `channels` | DB | Current channel count |
| `connectionsSinceBoot` | Memory | Total client connections since server start |
| `sessionsSinceBoot` | Memory | Total sessions created since server start |
| `messagesSinceBoot` | Memory | Total PRIVMSG/NOTICE messages since server start |
## Implementation
- **New `internal/stats` package** — atomic counters for boot-scoped metrics (`connectionsSinceBoot`, `sessionsSinceBoot`, `messagesSinceBoot`). Thread-safe via `sync/atomic`.
- **New DB queries** — `GetClientCount()` and `GetQueueEntryCount()` for current snapshot counts.
- **Healthcheck changes** — `Healthcheck()` now accepts `context.Context` to query the database. Response struct extended with all 7 new fields. DB-derived stats populated with graceful error handling (logged, not fatal).
- **Counter instrumentation** — Increments added at:
- `handleCreateSession` → `IncrSessions` + `IncrConnections`
- `handleRegister` → `IncrSessions` + `IncrConnections`
- `handleLogin` → `IncrConnections` (new client for existing session)
- `handlePrivmsg` → `IncrMessages` (covers both PRIVMSG and NOTICE)
- **Wired via fx** — `stats.Tracker` provided through Uber fx DI in both production and test setups.
## Tests
- `internal/stats/stats_test.go` — 5 tests covering all counter operations (100% coverage)
- `TestHealthcheckRuntimeStatsFields` — verifies all 7 new fields are present in the response
- `TestHealthcheckRuntimeStatsValues` — end-to-end: creates a session, joins a channel, sends a message, then verifies counts are nonzero
## README
Updated healthcheck documentation with full response shape, field descriptions, and project structure listing for `internal/stats/`.
Co-authored-by: user <user@Mac.lan guest wan>
Reviewed-on: #80
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>
Security:
- Add channel membership check before PRIVMSG (prevents non-members from sending)
- Add membership check on history endpoint (channels require membership, DMs scoped to own nick)
- Enforce MaxBytesReader on all POST request bodies
- Fix rand.Read error being silently ignored in token generation
Data integrity:
- Fix TOCTOU race in GetOrCreateChannel using INSERT OR IGNORE + SELECT
Build:
- Add CGO_ENABLED=0 to golangci-lint install in Dockerfile (fixes alpine build)
Linting:
- Strict .golangci.yml: only wsl disabled (deprecated in v2)
- Re-enable exhaustruct, depguard, godot, wrapcheck, varnamelen
- Fix linters-settings -> linters.settings for v2 config format
- Fix ALL lint findings in actual code (no linter config weakening)
- Wrap all external package errors (wrapcheck)
- Fill struct fields or add targeted nolint:exhaustruct where appropriate
- Rename short variables (ts->timestamp, n->bufIndex, etc.)
- Add depguard deny policy for io/ioutil and math/rand
- Exclude G704 (SSRF) in gosec config (CLI client takes user-configured URLs)
Tests:
- Add security tests (TestNonMemberCannotSend, TestHistoryNonMember)
- Split TestInsertAndPollMessages for reduced complexity
- Fix parallel test safety (viper global state prevents parallelism)
- Use t.Context() instead of context.Background() in tests
Docker build verified passing locally.
