feat(docker): add Dockerfile, Docker Compose, and deployment entrypoint

Multi-stage Dockerfile produces a lean image with the compiled SvelteKit
app (adapter-node) and the MCP server TypeScript source. A single image
supports two run modes selected via CMD: web (default) and mcp.

- docker-entrypoint.sh handles CA certificate install (PEM/DER auto-detected
  via openssl), SSH key permission fix for Windows-mounted keys, per-host
  HTTPS credential helpers for Bitbucket and GitLab, DB migrations, then
  starts the requested service
- docker-compose.yml runs web on :3000 and the MCP HTTP server on :3001,
  with the MCP container pointed at the web service via internal DNS
- .dockerignore excludes node_modules, build output, .env files, and *.db*

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

.dockerignore

@@ -0,0 +1,15 @@
+node_modules
+.svelte-kit
+build
+.output
+.env
+.env.*
+!.env.example
+*.db
+*.db-shm
+*.db-wal
+.git
+.claude
+prompts/
+docs/docs_cache_state.yaml
+.tmp/