docs: expand README quick start with full dev/debug setup

- Step-by-step backend setup: venv, secret key generation (openssl +
  Fernet), .env configuration with annotated minimum values
- VS Code launch.json snippets for backend (debugpy/uvicorn) and
  frontend (Chrome with source maps)
- Vite proxy detail (/api → :8000, /ws → ws://:8000)
- Backend pytest commands alongside existing frontend test section
- Playwright headed/UI mode instructions for E2E debugging
- Updated unit test count to 173; removed stale E2E count
- CLAUDE.md quick start trimmed to point at README for full setup

CLAUDE.md

@@ -3,16 +3,17 @@
 ## Quick Start
 
 ```bash
-# Backend (from backend/)
-python -m uvicorn main:app --host 0.0.0.0 --port 8000 --reload
+# Backend (from backend/, venv must be active)
+uvicorn main:app --host 0.0.0.0 --port 8000 --reload
 
 # Frontend (from frontend/)
-npx vite --host
+npm run dev
 ```
 
 - Backend API: http://localhost:8000 (docs: http://localhost:8000/docs)
-- Frontend: http://localhost:5173
-- Default admin: `admin` / (random, printed at first startup; reset via `python -c "from core.auth.utils import hash_password; print(hash_password('admin123'))"` then update SQLite)
+- Frontend: http://localhost:5173 (Vite proxies /api and /ws to :8000)
+- Default admin: `admin` / (random, printed at first startup)
+- Full setup instructions (secrets, venv, debug configs): see README.md
 
 ## Architecture
 
@@ -94,29 +95,13 @@ cd frontend && npx tsc --noEmit
 - **Arma 3 per-mission params**: `ServerConfig.missions` is now `list[MissionRotationItem]` (adds optional `params: dict`). A new `default_mission_params` field holds server-wide defaults. Config version bumped to `"1.1.0"`. `_render_server_cfg()` now emits a `class Missions { ... }` block when the rotation is non-empty; `class Params` inside each mission uses per-mission params → global defaults → omit (in that priority order). The `MissionRotationEntry.params` is edited per-row in the Missions tab via `MissionParamsEditor`; `default_mission_params` is edited in the Config tab via the `key-value` widget.
 - **Config version migration**: `migrate_config("1.0.0", ...)` backfills `params: {}` on each existing rotation entry and adds `default_mission_params: {}`. `normalize_section()` does the same on reads for stored rows that pre-date the migration run.
 
-## Known Bugs — Mods Tab (fix next session)
+## Mods Tab — Implementation Notes
 
-Three bugs prevent the Mods tab from working correctly:
-
-### Bug 1 — Save fails with TypeError (critical)
-`Arma3ModManager.set_enabled_mods()` calls `config_repo.upsert_section()` with wrong keyword argument names:
-- Passes `data=` → should be `config_data=`
-- Passes `expected_version=` → should be `expected_config_version=`
-- Missing required `game_type=` argument
-- Missing required `schema_version=` argument
-
-**File:** `backend/adapters/arma3/mod_manager.py`, `set_enabled_mods()` method (~line 127)
-
-### Bug 2 — Mods not applied on server start (critical)
-`service.py` `start_server()` reads mods from a `server_mods` JOIN `mods` table (SQLAlchemy query, ~line 246) — but those tables are never populated by the Mods tab UI. The correct source is `config_repo.get_section(server_id, "mods")["enabled_mods"]`. The start flow needs to read from `config_repo` instead of the dead `server_mods` table join.
-
-**File:** `backend/core/servers/service.py`, `start_server()` method (~line 242–255)
-
-### Bug 3 — Wrong mod folder location (UX)
-`list_available_mods()` scans the server root (`get_server_dir()`) for `@*` folders. Mods should live in a `mods/` subfolder: `{server_dir}/mods/@ModName`. Needs:
-1. Change scan path: `server_dir / "mods"` instead of `server_dir`
-2. Ensure the `mods/` subdirectory is created by `ensure_server_dirs` (add `"mods"` to the Arma3 `get_server_dir_layout()`)
-3. Update CLAUDE.md + user docs to say mods go in `D:/ImContainer/Arma3Server/{id}/mods/@ModName`
-
-**File:** `backend/adapters/arma3/mod_manager.py`, `list_available_mods()` and `_server_dir()` (~line 47–88)
-Also: `backend/adapters/arma3/adapter.py`, `get_server_dir_layout()` (add `"mods"` entry)
+- Mods go in `{server_data_dir}/{server_id}/mods/@ModName` (e.g. `D:/ImContainer/Arma3Server/1/mods/@CBA_A3/`)
+- Enabled mods config schema: `{"enabled_mods": [{"name": "@CBA_A3", "is_server_mod": false}]}`
+  - Old string-list format is auto-migrated to the dict format on read
+  - `is_server_mod: true` → `-serverMod=` arg; `false` → `-mod=` arg
+- `list_available_mods()` scans `{server_dir}/mods/` for `@*` directories
+- `set_enabled_mods()` stores the new dict format; validates names against disk
+- Server start reads mods from `game_configs` via `config_repo`, NOT from the dead `server_mods` table
+- Directory scaffold: all 4 Arma3 subdirs (`server/`, `battleye/`, `mpmissions/`, `mods/`) are created on server create and backfilled on startup; each gets a `README.txt` if not already present