Initial implementation of latent: film-effects editor + develop-later server

Canvas-based client-side editor (grain, vignette, halation, procedural
light leaks, color-cast presets) plus a small Express/SQLite server for
the two paths that need persistence: instant share links and delayed
"send to develop" links with a randomized reveal time.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

server/package.json

@@ -0,0 +1,15 @@
+{
+  "name": "latent-server",
+  "version": "0.1.0",
+  "private": true,
+  "type": "module",
+  "description": "Small server for latent's two persistence paths: share links and delayed development",
+  "scripts": {
+    "start": "node src/index.js",
+    "dev": "node --watch src/index.js"
+  },
+  "dependencies": {
+    "better-sqlite3": "^11.3.0",
+    "express": "^4.19.2"
+  }
+}