Switch to datastar-pro and stop tracking downloaded libs

Datastar-pro is fetched from a private Gitea repo (ryan/vendor-libs)
using VENDOR_TOKEN for CI/Docker builds, with a local fallback from
../optional/ for development. DaisyUI is pinned to v5.5.19 instead of
tracking latest. Downloaded files are now gitignored and fetched at
build time via 'task download', which is a dependency of both build
and live tasks.

AGENTS.md

@@ -9,6 +9,7 @@ Instructions for AI coding agents working in this repository.
 task live              # Hot-reload dev server (templ + tailwind + air)
 task build             # Production build to bin/games
 task run               # Build and run server
+task download          # Download pinned client-side libs (datastar-pro, daisyui)
 
 # Quality
 task test              # Run all tests: go test ./...
@@ -16,106 +17,80 @@ task lint              # Run linter: golangci-lint run
 
 # Single test
 go test -run TestName ./path/to/package
+go test -v -run TestHandleLogin_Success ./features/auth
 
 # Code generation
-task build:templ       # Compile .templ files
+task build:templ       # Compile .templ files (go tool templ generate)
-task build:styles      # Build TailwindCSS
+task build:styles      # Build TailwindCSS (go tool gotailwind)
-go generate ./...      # Run sqlc for DB queries
 ```
 
+Tools (templ, air, gotailwind, goose, sqlc) are managed via Go 1.25's `tool` directive in go.mod — no separate installs needed.
+
 ## Workflow Rules
 
 - **Never merge PRs without explicit user approval.** Create the PR, push changes, then wait.
-- Always use PRs via `tea` CLI - never push directly to main.
+- Always use PRs via `tea` CLI — never push directly to main.
 - Write semantic commit messages focusing on "why" not "what".
 
 ## Project Structure
 
 ```
 games/
-├── connect4/, snake/       # Game logic packages (pure Go)
+├── connect4/, snake/       # Game logic packages (pure Go, no HTTP)
 ├── features/               # Feature modules (handlers, routes, templates)
-│   ├── auth/               # Login/register
+│   ├── auth/               # Login/register (standard HTTP, not SSE)
-│   ├── c4game/             # Connect 4 UI
+│   ├── c4game/             # Connect 4 UI + services
-│   ├── snakegame/          # Snake UI
+│   ├── snakegame/          # Snake UI + services
 │   ├── lobby/              # Game lobby
 │   └── common/             # Shared components, layouts
-├── chat/                   # Reusable chat room (NATS + persistence)
+├── chat/                   # Reusable chat room (NATS + optional DB persistence)
+├── auth/                   # Password hashing/validation (pure, no HTTP)
 ├── db/                     # SQLite, migrations, sqlc queries
-├── assets/                 # Static files (embedded)
+├── cmd/downloader/         # Build-time tool: fetches datastar-pro + daisyui
-└── config/, logging/, nats/, sessions/, router/  # Infrastructure
+├── assets/                 # Static files (embedded in prod, filesystem in dev)
+└── config/, logging/, nats/, sessions/, router/, player/, version/
 ```
 
 ## Code Style
 
 ### Imports
 
-Organize in three groups: stdlib, third-party, local. The linter enforces this.
+Three groups separated by blank lines: stdlib, third-party, local. Enforced by goimports with `local-prefixes: github.com/ryanhamamura/games`.
 
 ```go
 import (
-    "context"
     "fmt"
     "net/http"
 
     "github.com/go-chi/chi/v5"
-    "github.com/rs/zerolog/log"
 
     "github.com/ryanhamamura/games/connect4"
-    "github.com/ryanhamamura/games/db/repository"
 )
 ```
 
-### Naming Conventions
-
-| Type | Convention | Examples |
-|------|------------|----------|
-| Files | lowercase, underscores | `config_dev.go`, `handlers.go` |
-| HTTP handlers | `Handle` prefix | `HandleGamePage`, `HandleLogin` |
-| Constructors | `New` prefix | `NewStore`, `NewRoom` |
-| Getters | `Get` prefix | `GetPlayerID`, `GetGame` |
-| Setup functions | `Setup` prefix | `SetupRoutes`, `SetupLogger` |
-| Types | PascalCase | `Game`, `Player`, `Instance` |
-| Status enums | `Status` prefix | `StatusWaitingForPlayer`, `StatusInProgress` |
-| Session keys | `Key` prefix | `KeyPlayerID`, `KeyUserID` |
-
 ### Error Handling
 
-1. **Wrap errors with context:**
+```go
-   ```go
+// Wrap errors with context
-   return fmt.Errorf("loading game %s: %w", id, err)
+return fmt.Errorf("loading game %s: %w", id, err)
-   ```
 
-2. **Return (result, error) tuples:**
+// Combine cleanup errors with errors.Join
-   ```go
+return nil, errors.Join(fmt.Errorf("pinging database: %w", err), DB.Close())
-   func loadGame(queries *repository.Queries, id string) (*Game, error)
-   ```
 
-3. **Best-effort operations** - use nolint comment:
+// Best-effort operations
-   ```go
+nc.Publish(subject, nil) //nolint:errcheck // best-effort notification
-   nc.Publish(subject, nil) //nolint:errcheck // best-effort notification
-   ```
 
-4. **HTTP errors:**
+// HTTP errors
-   ```go
+http.Error(w, "game not found", http.StatusNotFound)
-   http.Error(w, "game not found", http.StatusNotFound)
+http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
-   http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+
-   ```
+```
 
 ### Comments
 
 - Focus on **why**, not **how**. Avoid superfluous comments.
-- Package comments at top of primary file:
+- Package comments at top of primary file.
-  ```go
+- Function comments for exported functions.
-  // Package connect4 implements Connect 4 game logic, state management, and persistence.
-  package connect4
-  ```
-- Function comments for exported functions:
-  ```go
-  // DropPiece attempts to drop a piece in the given column.
-  // Returns (row placed, success).
-  func (g *Game) DropPiece(col, playerColor int) (int, bool)
-  ```
 
 ## Go Patterns
 
@@ -125,129 +100,119 @@ Handlers receive dependencies and return `http.HandlerFunc`:
 
 ```go
 func HandleGamePage(store *connect4.Store, sm *scs.SessionManager) http.HandlerFunc {
-    return func(w http.ResponseWriter, r *http.Request) {
+    return func(w http.ResponseWriter, r *http.Request) { /* ... */ }
-        // use store, sm here
-    }
 }
 ```
 
-### Mutex for Concurrent Access
+### Cleanup Function Returns
+
+Infrastructure init functions return a cleanup func the caller defers:
 
 ```go
-type Store struct {
+cleanupDB, err := db.Init(cfg.DBPath)
-    games   map[string]*Instance
+defer cleanupDB()
-    gamesMu sync.RWMutex
-}
-
-func (s *Store) Get(id string) (*Instance, bool) {
-    s.gamesMu.RLock()
-    defer s.gamesMu.RUnlock()
-    inst, ok := s.games[id]
-    return inst, ok
-}
 ```
 
-### Build Tags for Environment
+### Store/Instance Pattern
 
-```go
+Game state uses a two-tier pattern: a thread-safe **Store** (map + RWMutex) holding **Instance** wrappers (individual game + own mutex + DB queries). Stores lazy-load from DB on cache miss.
-//go:build dev
 
-//go:build !dev
+### Build Tags
-```
 
-### Embedded Filesystems
+`//go:build dev` and `//go:build !dev` switch behavior for static asset serving (filesystem vs embedded hashfs) and config loading.
-
-```go
-//go:embed assets
-var assets embed.FS
-
-//go:embed migrations/*.sql
-var MigrationFS embed.FS
-```
-
-### Graceful Shutdown
-
-```go
-eg, egctx := errgroup.WithContext(ctx)
-eg.Go(func() error { return server.ListenAndServe() })
-eg.Go(func() error {
-    <-egctx.Done()
-    return server.Shutdown(context.Background())
-})
-return eg.Wait()
-```
 
 ## Templ + Datastar Patterns
 
-### SSE Connection with Disabled Cancellation
+### Architecture: Everything Is a Stream
 
-Datastar cancels SSE on user interaction by default. Disable for persistent connections:
+The core mental model: **the server owns all state and continuously projects it to the browser over SSE**. There is no client-side state management. The browser connects to an event stream, and the server pushes full HTML fragments whenever something changes. Datastar morphs these into the DOM — the client is a thin rendering surface.
+
+User actions (clicks, keypresses) trigger short POST/DELETE requests back to the server. The server mutates state, publishes a NATS signal, and every connected SSE stream picks up the change and re-renders. The client never needs to know what changed — it just receives the new truth and morphs to match.
+
+This means: **always send whole components down the wire.** Don't try to diff or send minimal patches. Render the full templ component, call `sse.PatchElementTempl()`, and let Datastar's morph handle the rest. The only exception is appending to a list (e.g. chat messages).
+
+**Signals follow command-query segregation.** Signals are *commands* — they carry the user's intent to the server (form input values, button clicks). The SSE stream is the *query* — it continuously projects the server's truth into the DOM. Keep signals thin: form input buffers (`chatMsg`, `nickname`), pure UI state the server never needs (`activeTab`), and request indicators. Don't use signals to hold application state — that arrives from the server via SSE.
+
+### SSE Event Loop
+
+Both game event handlers follow the same structure:
+1. Subscribe to NATS channels **before** creating SSE (avoids missed messages)
+2. Send initial full-state patch
+3. `select` loop over: context done, game updates (drain channel first), chat messages (append), 1-second heartbeat (full re-render)
 
 ```go
+// Handler side — long-lived SSE with Brotli compression
+sse := datastar.NewSSE(w, r, datastar.WithCompression(
+    datastar.WithBrotli(datastar.WithBrotliLevel(5)),
+))
+sse.PatchElementTempl(components.GameBoard(game))
+
+// Template side — disable Datastar's default SSE cancellation on interaction
 data-init={ fmt.Sprintf("@get('/games/%s/events',{requestCancellation:'disabled'})", g.ID) }
 ```
 
-### Prevent Script Duplication on SSE Patches
+### Client-Server Interactions
-
-Use `templ.NewOnceHandle()` for scripts in components that get patched:
 
 ```go
-var scriptHandle = templ.NewOnceHandle()
+// Trigger SSE actions from templates
+data-on:click={ datastar.PostSSE("/games/%s/drop?col=%d", g.ID, colIdx) }
+data-on:click={ datastar.DeleteSSE("/games/%s", g.ID) }
 
-templ MyComponent() {
+// Read client signals in handlers
-    <div id="my-component">...</div>
+var signals struct { ChatMsg string `json:"chatMsg"` }
-    @scriptHandle.Once() {
+datastar.ReadSignals(r, &signals)
-        @myScript()
+
-    }
+// Clear input after submission
-}
+sse.MarshalAndPatchSignals(map[string]any{"chatMsg": ""})
+
+// Redirect via SSE
+sse.Redirectf("/games/%s", newGame.ID())
 ```
 
-### Conditional Classes with templ.KV
+### Appending Elements (Chat Messages)
+
+The one exception to whole-component morphing is chat, where messages are appended individually:
 
 ```go
-class={
+sse.PatchElementTempl(
-    "status status-sm",
+    chatcomponents.ChatMessage(msg, cfg),
-    templ.KV("status-success", isConnected),
+    datastar.WithSelectorID("c4-chat-history"),
-    templ.KV("status-error", !isConnected),
+    datastar.WithModeAppend(),
-}
+)
 ```
 
-### Datastar SSE Responses
+### Datastar Template Attributes
 
-```go
+- `data-signals` — declare reactive state
-sse := datastar.NewSSE(w, r)
+- `data-bind` — two-way input binding
-sse.MergeFragmentTempl(components.GameBoard(game))
+- `data-show` — conditional visibility
+- `data-class` — reactive CSS classes
+- `data-morph-ignore` — prevent SSE from overwriting an element (e.g. chat input)
+
+## Testing
+
+```bash
+task test                                          # All tests
+go test -run TestHandleLogin_Success ./features/auth  # Single test
+go test -v ./features/auth                         # Verbose package
 ```
 
+- Use `testutil.NewTestDB(t)` for tests needing a database
+- Use `testutil.NewTestSessionManager(db)` for session-aware tests
+- Use `config.LoadForTest()` to set safe defaults without .env
+- Tests use external test packages (`package auth_test`)
+
 ## Tech Stack
 
 | Layer | Technology |
 |-------|------------|
 | Templates | templ (type-safe HTML) |
-| Reactivity | Datastar (SSE-driven) |
+| Reactivity | Datastar Pro (SSE-driven) |
 | CSS | TailwindCSS v4 + daisyUI |
 | Router | chi/v5 |
-| Sessions | scs/v2 |
+| Sessions | scs/v2 (SQLite-backed) |
 | Database | SQLite (modernc.org/sqlite) |
-| Migrations | goose |
+| Migrations | goose (embedded SQL) |
 | SQL codegen | sqlc |
-| Pub/sub | Embedded NATS |
+| Pub/sub | Embedded NATS (nil-payload signals) |
-| Logging | zerolog |
+| Logging | zerolog + slog (bridged via slog-zerolog) |
-
-## Testing
-
-```bash
-# All tests
-task test
-
-# Single test
-go test -run TestDropPiece ./connect4
-
-# With verbose output
-go test -v -run TestDropPiece ./connect4
-
-# Test a package
-go test ./connect4/...
-```
-
-Use `testutil.SetupTestDB()` for tests requiring database access.