test: comprehensive test expansion — 330+ to 525+ tests, close M11b coverage gaps

Add 195+ new tests across service, handler, connector, and integration layers:
- Service tests: team (23), owner (21), agent_group (25), issuer (18), issuer_adapter (6)
- Handler tests: teams (26), owners (21)
- NGINX target connector tests (13): config validation, deployment, reload
- Integration tests: 19 M11b endpoint subtests (teams, owners, agent groups CRUD)
- CI pipeline: add ./internal/connector/target/... to test coverage path
- Docs: update test counts to 525+ across README, architecture, CLAUDE.md

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/architecture.md

@@ -615,19 +615,21 @@ For production, you would also add an ingress controller, TLS termination for th
 
 ## Testing Strategy
 
-certctl uses a layered testing approach aligned with the handler → service → repository architecture, with 330+ tests across five layers (service, handler, integration, connector, and frontend). The goal is high-confidence regression prevention at the service and handler layers, where the most complex business logic lives, combined with integration tests that exercise the full request path from HTTP to database.
+certctl uses a layered testing approach aligned with the handler → service → repository architecture, with 525+ tests across five layers (service, handler, integration, connector, and frontend). The goal is high-confidence regression prevention at the service and handler layers, where the most complex business logic lives, combined with integration tests that exercise the full request path from HTTP to database.
 
-**Service layer unit tests** (`internal/service/*_test.go`) — 99 test functions across 10 files with mock repositories. These test all business logic in isolation: certificate CRUD with validation, agent lifecycle (registration, heartbeat, CSR submission with both keygen modes), job state machine (creation, processing, cancellation, retry logic), policy evaluation (all 5 rule types, violation creation), renewal and issuance flow (server-side and agent-side keygen paths), and notification deduplication (threshold tag matching, channel routing). Mock repositories are simple structs with function fields, avoiding heavy mocking frameworks — this keeps tests readable and avoids coupling to mock library APIs.
+**Service layer unit tests** (`internal/service/*_test.go`) — 192 test functions across 14 files with mock repositories. These test all business logic in isolation: certificate CRUD with validation, agent lifecycle (registration, heartbeat, CSR submission with both keygen modes), job state machine (creation, processing, cancellation, retry logic), policy evaluation (all 5 rule types, violation creation), renewal and issuance flow (server-side and agent-side keygen paths), notification deduplication (threshold tag matching, channel routing), team/owner/agent group CRUD with pagination and audit recording, issuer service CRUD with connection testing, and the issuer connector adapter (type translation between connector and service layers). Mock repositories are simple structs with function fields, avoiding heavy mocking frameworks — this keeps tests readable and avoids coupling to mock library APIs.
 
-**Handler layer tests** (`internal/api/handler/*_test.go`) — 165 test functions across 9 files using Go's `httptest` package. Every handler file has a corresponding test file: certificates (22 tests), agents (28 tests), jobs (21 tests including approve/reject), notifications (11 tests), policies (19 tests), profiles (18 tests), issuers (17 tests), targets (17 tests), and agent groups (12 tests). Each test file follows the same pattern: a mock service struct with function fields, `httptest.NewRecorder` for capturing responses, and a shared `contextWithRequestID()` helper. Tests cover the happy path, input validation (missing fields, invalid JSON, empty IDs), error propagation from the service layer, method-not-allowed responses, and pagination parameters.
+**Handler layer tests** (`internal/api/handler/*_test.go`) — 212 test functions across 11 files using Go's `httptest` package. Every handler file has a corresponding test file: certificates (22 tests), agents (28 tests), jobs (21 tests including approve/reject), notifications (11 tests), policies (19 tests), profiles (18 tests), issuers (17 tests), targets (17 tests), agent groups (12 tests), teams (26 tests), and owners (21 tests). Each test file follows the same pattern: a mock service struct with function fields, `httptest.NewRecorder` for capturing responses, and a shared `contextWithRequestID()` helper. Tests cover the happy path, input validation (missing fields, invalid JSON, empty IDs, name length limits), error propagation from the service layer, method-not-allowed responses, and pagination parameters.
 
-**Integration tests** (`internal/integration/`) — Two test files exercising the full stack from HTTP request through router, handler, service, and postgres repository layers. `lifecycle_test.go` has 11 subtests covering the complete certificate lifecycle: team/owner creation, certificate creation, issuer verification, renewal trigger, job verification, agent registration, CSR submission, deployment, and status reporting. `negative_test.go` has 14 subtests covering error paths: nonexistent resource lookups (404s), invalid request bodies (malformed JSON, missing required fields), invalid CSR submission, heartbeat for nonexistent agents, wrong HTTP methods on list endpoints, empty list responses, renewal on nonexistent certificates, and expired certificate lifecycle. Both use a shared `setupTestServer()` that builds a fully-wired server with real postgres repositories and the Local CA issuer connector.
+**Integration tests** (`internal/integration/`) — Two test files exercising the full stack from HTTP request through router, handler, service, and postgres repository layers. `lifecycle_test.go` has 11 subtests covering the complete certificate lifecycle: team/owner creation, certificate creation, issuer verification, renewal trigger, job verification, agent registration, CSR submission, deployment, and status reporting. `negative_test.go` has 14 subtests covering error paths plus 19 M11b endpoint tests: nonexistent resource lookups (404s), invalid request bodies (malformed JSON, missing required fields), invalid CSR submission, heartbeat for nonexistent agents, wrong HTTP methods on list endpoints, empty list responses, renewal on nonexistent certificates, expired certificate lifecycle, and team/owner/agent group CRUD validation (create with name validation, get not found, list empty, delete, method not allowed). Both use a shared `setupTestServer()` that builds a fully-wired server with real postgres repositories and the Local CA issuer connector.
 
 **Frontend tests** (`web/src/api/client.test.ts`, `web/src/api/utils.test.ts`) — 53 Vitest tests covering the API client and utility functions. The API client tests mock `globalThis.fetch` and verify all endpoint functions (certificates, agents, jobs, policies, issuers, targets, notifications, audit, health) send correct HTTP methods, URLs, headers, and request bodies. They also test API key management (store/retrieve/clear), auth header propagation, 401 event dispatching, and error handling (server messages, error fields, status text fallback). The utility tests use `vi.useFakeTimers()` for deterministic date testing and cover `formatDate`, `formatDateTime`, `timeAgo`, `daysUntil`, and `expiryColor`. The test environment uses jsdom with `@testing-library/jest-dom` matchers.
 
-**CI pipeline** (`.github/workflows/ci.yml`) — Two parallel jobs: Go (build, vet, test with coverage, coverage threshold enforcement) and Frontend (TypeScript type check, Vitest test suite, Vite production build). The Go job runs all tests with `-coverprofile`, then enforces coverage thresholds: service layer must be at least 30% (current: ~35%) and handler layer must be at least 50% (current: ~63%). These thresholds act as regression floors — they can only go up. The service layer threshold is deliberately lower because much of the service code depends on postgres repositories and external connectors that require real infrastructure to test meaningfully. Connector tests are included via `./internal/connector/issuer/...` (includes Local CA, ACME, and step-ca packages with unit tests for certificate signing logic, DNS solver, and issuer validation). The Frontend job runs `npx vitest run` between the TypeScript check and production build steps.
+**CI pipeline** (`.github/workflows/ci.yml`) — Two parallel jobs: Go (build, vet, test with coverage, coverage threshold enforcement) and Frontend (TypeScript type check, Vitest test suite, Vite production build). The Go job runs all tests with `-coverprofile`, then enforces coverage thresholds: service layer must be at least 30% (current: ~35%) and handler layer must be at least 50% (current: ~63%). These thresholds act as regression floors — they can only go up. The service layer threshold is deliberately lower because much of the service code depends on postgres repositories and external connectors that require real infrastructure to test meaningfully. Connector tests are included via `./internal/connector/issuer/...` and `./internal/connector/target/...` (covers Local CA, ACME, step-ca, NGINX, Apache, and HAProxy packages with unit tests for certificate signing logic, DNS solver, issuer validation, and deployment flows). The Frontend job runs `npx vitest run` between the TypeScript check and production build steps.
 
-**What's not tested and why:** Postgres repository implementations (`internal/repository/postgres/`) require a real database and are tested only through integration tests, not unit tests. Target connectors for F5 BIG-IP and IIS depend on real infrastructure or complex mocks. Apache httpd and HAProxy connectors have unit tests (7 tests each) covering config validation, deployment, and validation flows. Scheduler loops are time-dependent and tested manually during development. The ACME connector requires a real ACME server (tested manually against Let's Encrypt staging). These are all candidates for future expansion as the test infrastructure matures.
+**Connector tests** (`internal/connector/`) — 23 test functions covering issuer and target connectors. The Local CA connector has tests for self-signed and sub-CA modes (RSA, ECDSA, config validation, non-CA cert rejection). The ACME DNS solver has 6 tests for script-based DNS-01 challenges. The step-ca connector has tests with a mock HTTP server for issuance, renewal, revocation, and error paths. The NGINX target connector has 13 tests covering config validation, certificate deployment (file writing, permissions, validate/reload commands), and deployment validation. Apache httpd and HAProxy connectors each have 3 tests covering config validation, deployment, and validation flows.
+
+**What's not tested and why:** Postgres repository implementations (`internal/repository/postgres/`) require a real database and are tested only through integration tests, not unit tests. Target connectors for F5 BIG-IP and IIS are interface stubs (implementation planned for V2). Scheduler loops are time-dependent and tested manually during development. The ACME connector requires a real ACME server (tested manually against Let's Encrypt staging). These are all candidates for future expansion as the test infrastructure matures.
 
 ## What's Next