Implements the Pansy v1 scaffold (epic #20, phase 0).

#1 Backend: Go module (pure-Go, builds with CGO_ENABLED=0), env config,
   gin server with slog + recovery + /api/v1/healthz, modernc SQLite store
   with WAL/busy_timeout/foreign_keys pragmas, embedded numbered-migration
   runner, full initial schema (users, sessions, gardens, garden_shares,
   garden_objects, plants, plantings), domain structs + sentinel errors,
   graceful shutdown.

#2 Frontend: Vite + React 19 + TS (strict) + Tailwind 4 + TanStack
   Router/Query, typed /api/v1 fetch wrapper (ApiError carries status +
   body so later issues can read 409 conflict rows), dev proxy /api -> :8080,
   responsive app shell with stub pages for all five routes.

#3 Single binary: //go:embed of the web build with a committed placeholder,
   SPA fallback (deep links, immutable asset caching, JSON 404 for unmatched
   /api and missing assets), Makefile (web/build/dev/test), README quickstart
   + env var table.

Verified: go build/vet/test clean (CGO off); binary migrates idempotently and
serves healthz; web tsc + build clean; integrated binary serves the SPA, deep
links, and correct cache headers; app mounts and navigates all five routes at
desktop and 375px widths.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01JdQpdYYsTgtkJBxbcpAszi

@@ -7,0 +33,4 @@
+```
+
+Open http://localhost:8080 — one process serves both the JSON API and the app.
+

@@ -0,0 +57,4 @@
+			}
+			// Vite emits content-hashed filenames under assets/, so those are safe
+			// to cache forever; index.html must always revalidate to pick up new builds.
+			if strings.HasPrefix(name, "assets/") {

@@ -0,0 +85,4 @@
+	c.Data(http.StatusOK, "text/html; charset=utf-8", index)
+}
+
+// writeAPIError writes pansy's standard JSON error envelope.

@@ -0,0 +57,4 @@
+}
+
+// RegistrationOpen reports whether local self-service signup is allowed.
+func (c *Config) RegistrationOpen() bool {

@@ -0,0 +65,4 @@
+// fails: invalid numeric/boolean values fall back to the default and are logged.
+func Load() *Config {
+	cfg := &Config{
+		Port:         envInt("PANSY_PORT", 8080),

@@ -0,0 +37,4 @@
+
+	ShapeRect    = "rect"
+	ShapeCircle  = "circle"
+	ShapePolygon = "polygon" // reserved for post-v1

@@ -0,0 +90,4 @@
+	); err != nil {
+		return fmt.Errorf("store: record migration %d: %w", m.version, err)
+	}
+	return tx.Commit()

@@ -0,0 +22,4 @@
+    version       INTEGER NOT NULL DEFAULT 1,
+    created_at    TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now')),
+    updated_at    TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ', 'now'))
+);

@@ -0,0 +60,4 @@
+// the required pragmas, and reports whether it is an in-memory database. It
+// accepts a bare filename, a path with existing query parameters, or a full
+// file: URI, and merges the pragmas without clobbering any the user supplied.
+func buildDSN(path string) (dsn string, memory bool) {

@@ -0,0 +69,4 @@
+		query = q
+	}
+
+	// Detect in-memory precisely: the exact ":memory:" token, or an explicit

@@ -0,0 +86,4 @@
+	if err != nil {
+		t.Fatalf("insert user: %v", err)
+	}
+	uid, _ := res.LastInsertId()

@@ -0,0 +44,4 @@
+}
+
+function buildUrl(path: string, params?: Params): string {
+  const url = BASE + path

@@ -0,0 +86,4 @@
+
+  // Serialize before the try so a JSON.stringify failure (e.g. a circular value)
+  // surfaces as itself, not as a misleading "cannot reach the server" error.
+  const requestBody = body !== undefined ? JSON.stringify(body) : undefined

@@ -0,0 +105,4 @@
+    throw new ApiError('Cannot reach the pansy server.', 0, null)
+  }
+
+  const payload = await parseBody(res)