feat: initial Phase 1 implementation — core framework + Docker

- Data types (SManga, SChapter, Page, MangasPage, all Filter variants)
- Source interfaces (Source, CatalogueSource) with MD5-based ID generation matching Tachiyomi/Suwayomi
- HTTP client with per-host rate limiting, cookie jar, and 429 retry
- FlareSolverr v1 client (FLARESOLVERR_URL env)
- Generic GraphQL POST helper
- goquery HTML parser wrappers
- Source registry (panics on duplicate ID)
- Multi-stage Dockerfile (golang:1.26-alpine + distroless) and compose.yml (postgres, flaresolverr, app)

.gitignore

@@ -0,0 +1,17 @@
+# Binaries
+/goyomi
+/cmd/server/server
+
+# Environment
+.env
+.env.*
+
+# Go tooling
+*.test
+*.out
+/vendor/
+
+# IDE
+.idea/
+.vscode/
+*.swp