docs: document full API surface in OpenAPI spec (v0.26.0)

Went from 14 to ~100 documented endpoints in lib/openapi.ts — pantry,
meal-plans, shopping-lists, collections, users/social, ai/*, webhooks,
conversations, notifications, and admin routes now all appear in
/docs with accurate request/response schemas. No auth/route changes.

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

apps/web/lib/changelog.ts

@@ -1,5 +1,5 @@
 // Mirrors CHANGELOG.md at the repo root — update both together.
-export const APP_VERSION = "0.25.1";
+export const APP_VERSION = "0.26.0";
 
 export type ChangelogEntry = {
   version: string;
@@ -11,6 +11,13 @@ export type ChangelogEntry = {
 };
 
 export const CHANGELOG: ChangelogEntry[] = [
+  {
+    version: "0.26.0",
+    date: "2026-07-14 10:20",
+    added: [
+      "**API Reference (`/docs`) now covers the full API**: went from 14 documented endpoints to all ~100 — pantry, meal plans, shopping lists, collections, users/social, AI generation, webhooks, conversations, notifications, and admin routes are now all documented with request/response schemas.",
+    ],
+  },
   {
     version: "0.25.1",
     date: "2026-07-14 09:40",