Phase 2: document CRUD + auto-save

Backend internal/docs: chi sub-router (list/create/get/update/delete)
mounted at /api/docs, scoped to the local user. Create uses RETURNING;
update is a COALESCE partial-update so rename and full editor save share
one PUT. JSON 404/400 errors; handlers_test.go walks the lifecycle.

Frontend: api/client.ts, useAutoSave (1.5s debounce + saveNow flush
before doc switch), EditorCore (Tiptap StarterKit/Underline/TextAlign/
Placeholder/CharacterCount) + Toolbar, DocList/DocListItem, StatusBar,
and an App.tsx that orchestrates load/select/create/delete with
optimistic sidebar patching. content + content_text + word_count are
emitted together on every edit. .petal-prose styling (Lora body, Nunito
headings).

Verified: tsc clean, vite build, go build, full CRUD smoke test incl.
CJK title round-trip and SPA serve.

Claude-Session: https://claude.ai/code/session_016Yr6jELuRc7hyzYLccQKZd

cmd/server/main.go

@@ -12,6 +12,7 @@ import (
 
 	"gitea.parodia.dev/drwily/petal/internal/config"
 	"gitea.parodia.dev/drwily/petal/internal/db"
+	"gitea.parodia.dev/drwily/petal/internal/docs"
 	"gitea.parodia.dev/drwily/petal/web"
 )
 
@@ -36,6 +37,8 @@ func main() {
 			w.Header().Set("Content-Type", "application/json")
 			_, _ = w.Write([]byte(`{"status":"ok"}`))
 		})
+
+		api.Mount("/docs", docs.New(database).Routes())
 	})
 
 	// Everything else: serve the embedded SPA (with index.html fallback for client routing).