Add homelab CD pipeline, semantic releases, MIT license, and docs

[memetics19]

Summary

Adds an end-to-end release-and-deploy pipeline for Pulse, project licensing,
docs, and a committed commit-policy guardrail. On merge to main, release-please
proposes a version; merging the release PR tags vX.Y.Z, builds and pushes the
image to GHCR, and deploys to the homelab over Netbird + SSH. Tests gate every
step.

What's included

CI/CD

• release-please.yml — semantic versioning from Conventional Commits (config + manifest seeded at 0.0.0).
• release.yml — now: test → build/push GHCR image → deploy job (needs: release) that joins Netbird, SSHes to
  ubuntu@10.2.0.115, and runs docker compose pull && up -d. Release/changelog ownership moved to release-please.
• deploy/docker-compose.homelab.yml — pulls ghcr.io/memetics19/pulse (no local build).

Build fix / refactor

• is_active is now a real Go bool (monitors + infra_agents) via sqlc column override + regeneration, with all consumers,
  the import CLI, and the admin UI updated.

Guardrail

• .githooks/{commit-msg,pre-commit} + CONTRIBUTING.md: reject AI/co-author trailers and un-gofmt'd Go. Enable with git config core.hooksPath .githooks.

Project / docs

• LICENSE.md (MIT) referenced from README.
• docs/deployment.md (in nav), status-page GIF wiring + capture recipe, getting-started import/clone-URL fixes.

Breaking change

is_active in monitor and agent JSON is now boolean (true/false) instead of
integer (0/1), on both request and response sides of /api/monitors and
/api/agents. The bundled UI and CLI are updated; external API clients must adapt.

Before deploy works (post-merge)

• Add secrets: NETBIRD_SETUP_KEY, NETBIRD_MANAGEMENT_URL (if self-hosted), SSH_PRIVATE_KEY, SSH_HOST_FINGERPRINT,
  DEPLOY_HOST=10.2.0.115, DEPLOY_USER=ubuntu. (PULSE_TOKEN exists.)
• Host 10.2.0.115: docker+compose, git clone … ~/pulse, authorize deploy key, GHCR package public or docker login,
  docker compose -f deploy/docker-compose.homelab.yml up -d (see docs/deployment.md).
• Drop docs/assets/status-page.gif (README embed is commented out until then).
• git config core.hooksPath .githooks locally to activate the guardrail.

Test plan / verification

• go build + go test ./... -count=1: api 18 pkgs ✓, agent ✓, cli ✓
• UI npx tsc --noEmit ✓
• Workflows + compose + mkdocs YAML parse ✓; release-please-*.json valid ✓
• docker compose -f deploy/docker-compose.homelab.yml config ✓
• commit-msg hook tested: rejects co-author/attribution, accepts clean ✓