refactor(db): rename redirect_path→redirect, add uid/addLog helpers, simplify Caddy CRUD

- Rename caddy.redirect_path to caddy.redirect across schema, server, frontend and docs
- Remove obsolete ALTER TABLE migration (fresh-install model has no migrations)
- Move uid() from server.ts to server-db.ts for shared use
- Add addLog() general helper (prepared statement, shared timestamp support) and
  replace ~24 inline INSERT INTO logs calls throughout server.ts
- Caddy CRUD now takes CaddyRouteInput object instead of positional arguments;
  add/update reuse getCaddyRouteById() to avoid duplicate SELECT

ARCHITECTURE.md

@@ -282,7 +282,7 @@ CREATE TABLE IF NOT EXISTS caddy (
     upstream      TEXT NOT NULL,
     tls           INTEGER NOT NULL DEFAULT 1,
     compress      INTEGER NOT NULL DEFAULT 1,
-    redirect_path TEXT NOT NULL DEFAULT '',   -- optional 'redir / <path>' for the bare root
+    redirect      TEXT NOT NULL DEFAULT '',   -- optional 'redir / <path>' for the bare root
     created_at    TEXT DEFAULT (datetime('now'))
 );
 ```
@@ -464,8 +464,8 @@ Manual:  POST /api/semaphore/trigger/{bookingId}  body { type: 'setup'|'teardown
 ```
 buildCaddyfile():
   { local_certs }                          # global block
-  per custom route { [encode] [tls internal] [redir / <redirect_path>] reverse_proxy <upstream> { … } }
-  redirect_path set → `redir / <path>` redirects only the bare root '/'
+  per custom route { [encode] [tls internal] [redir / <redirect>] reverse_proxy <upstream> { … } }
+  redirect set → `redir / <path>` redirects only the bare root '/'
     (other paths pass through; e.g. CheckMK served at /<site>/check_mk/)
   every reverse_proxy block carries standard forwarding headers:
     header_up X-Forwarded-Proto {scheme}
@@ -716,7 +716,7 @@ Backup  :  ghostgrid.db + ghostgrid.db-wal + ghostgrid.db-shm
 ```
 GhostGrid/
 +-- server.ts                 # Express app: all routes, auth, integrations, background jobs
-+-- server-db.ts              # SQLite connection, full schema, settings/Caddy helpers
++-- server-db.ts              # SQLite connection, full schema, settings/Caddy/log helpers (uid, addLog)
 +-- index.html                # Vite HTML entry (#root > src/main.tsx); links /favicon.svg
 +-- public/
 |   +-- favicon.svg           # app favicon (GhostGrid logo; served at site root by Vite)