Add forgejo (with shared postgres), docs/ideas; fix ENOTDIR in local catalog listing

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

services/postgres/metadata.json

@@ -0,0 +1,44 @@
+{
+  "id": "postgres",
+  "name": "PostgreSQL",
+  "description": "Shared PostgreSQL database for homelab services (Forgejo today, future apps later).",
+  "version": "17.0.0",
+  "category": "database",
+  "tags": ["database", "sql", "postgres"],
+  "author": "PostgreSQL Global Development Group",
+  "license": "PostgreSQL",
+  "homepage": "https://www.postgresql.org/",
+  "documentation": "https://hub.docker.com/_/postgres",
+  "compose": {
+    "image": "postgres:17",
+    "container_name": "homelab-postgres",
+    "restart": "unless-stopped",
+    "environment": [
+      "POSTGRES_USER=${PG_USER}",
+      "POSTGRES_PASSWORD=${PG_PASSWORD}",
+      "POSTGRES_DB=${PG_DB}"
+    ],
+    "volumes": ["pg_data:/var/lib/postgresql/data"],
+    "networks": ["homelab"],
+    "healthcheck": {
+      "test": ["CMD-SHELL", "pg_isready -U ${PG_USER} -d ${PG_DB}"],
+      "interval": "10s",
+      "timeout": "5s",
+      "retries": 5
+    }
+  },
+  "volumes": { "pg_data": {} },
+  "networks": { "homelab": { "external": true } },
+  "env": [
+    { "name": "PG_USER", "label": "Postgres user", "default": "homelab" },
+    {
+      "name": "PG_PASSWORD",
+      "label": "Postgres password",
+      "description": "Auto-generated on first install and stored in ~/.homelab/services/postgres/.env",
+      "secret": true,
+      "generate": true
+    },
+    { "name": "PG_DB", "label": "Database name", "default": "forgejo" }
+  ],
+  "notes": "No host port published — reachable only inside the homelab docker network as `homelab-postgres`."
+}