feat(cli): add minimal trigger surface

[santoshkumarradha]

Closes #576

Summary

• Add root-level af call, af ls, and af tail commands for the minimal human trigger surface.
• Add reasoner catalog and execution event stream API routes used by the CLI.
• Add focused CLI/handler unit tests and a functional Docker e2e covering call/schema/ls/async/tail.

Verification

• go test ./cmd/af ./internal/cli ./internal/handlers ./internal/server -run 'Test(NewRoot|ResolveCall|ValidateInput|ExitCode|ListReasoners|StreamExecution|SetupRoutes|StartAdmin)'\n- go test ./cmd/af ./internal/cli ./internal/handlers\n- go build -tags "sqlite_fts5" -o /tmp/af-issue-576 ./cmd/af\n- python3 -m py_compile tests/functional/tests/test_af_trigger_cli.py\n- OPENROUTER_API_KEY=dummy PYTEST_ARGS='-q tests/test_af_trigger_cli.py' docker compose -f docker/docker-compose.local.yml -f <(printf 'services:\\n control-plane:\\n ports: !reset []\\n') up --build --abort-on-container-exit --exit-code-from test-runner\n\nNote: the functional Docker run used a transient compose override to remove the host 8080:8080 publish because port 8080 was already in use locally; service-to-service traffic still used control-plane:8080 inside Docker.

[github-actions]

📊 Coverage gate

Thresholds from .coverage-gate.toml: per-surface ≥ 86%, aggregate ≥ 88%, max per-surface regression ≤ 1.0 pp, max aggregate regression ≤ 0.50 pp.

Surface	Current	Baseline	Δ
control-plane	87.40%	87.30%	↑ +0.10 pp	🟡
sdk-go	92.10%	90.70%	↑ +1.40 pp	🟢
sdk-python	93.73%	93.63%	↑ +0.10 pp	🟢
sdk-typescript	92.80%	92.56%	↑ +0.24 pp	🟢
web-ui	89.93%	90.01%	↓ -0.08 pp	🟡
aggregate	89.00%	89.01%	↓ -0.01 pp	🟡

✅ Gate passed

No surface regressed past the allowed threshold and the aggregate stayed above the floor.

[github-actions]

📐 Patch coverage gate

Threshold: 80% on lines this PR touches vs origin/main (from .coverage-gate.toml:thresholds.min_patch).

Surface	Touched lines	Patch coverage	Status
control-plane	1053	80.00%	✅
sdk-go	0	—	➖ no changes
sdk-python	0	—	➖ no changes
sdk-typescript	0	—	➖ no changes
web-ui	0	—	➖ no changes

✅ Patch gate passed

Every surface whose lines were touched by this PR has patch coverage at or above the threshold.

[santoshkumarradha]

@AbirAbbas once this is merged, can we update readme of *-af examples with cli as primary call method and curl as secondry one for ease of friction free first experience?