feat(life): add community feed for user posts

Add life_posts schema and CRUD API endpoints
Implement LifeView with inline composer and feed display

backend/db/schema.sql

@@ -119,6 +119,21 @@ CREATE TABLE IF NOT EXISTS daily_checklist_items (
 CREATE INDEX IF NOT EXISTS daily_checklist_items_sort_order_idx
   ON daily_checklist_items(sort_order, id);
 
+CREATE TABLE IF NOT EXISTS life_posts (
+  id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+  body text NOT NULL CHECK (length(body) BETWEEN 1 AND 2000),
+  created_by_user_id integer REFERENCES users(id) ON DELETE SET NULL,
+  updated_by_user_id integer REFERENCES users(id) ON DELETE SET NULL,
+  created_at timestamptz NOT NULL DEFAULT now(),
+  updated_at timestamptz NOT NULL DEFAULT now()
+);
+
+ALTER TABLE life_posts DROP COLUMN IF EXISTS link_url;
+ALTER TABLE life_posts DROP COLUMN IF EXISTS link_title;
+
+CREATE INDEX IF NOT EXISTS life_posts_created_at_idx
+  ON life_posts(created_at DESC, id DESC);
+
 CREATE TABLE IF NOT EXISTS skills (
   id integer GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
   name text NOT NULL UNIQUE,