feat: single port config (dashboard on port, datasette on port+1)

- ARGUS_PORT now sets dashboard port, datasette auto-derives as port+1
- Dashboard dynamically injects correct datasette URL
- Simplifies multi-agent deployment (each agent gets own port namespace)
- Removed ARGUS_DASHBOARD_PORT env var

README.md

@@ -83,8 +83,7 @@ Environment variables:
 | Variable | Default | Description |
 |----------|---------|-------------|
 | `ARGUS_DB` | `~/.argus/argus.db` | Database path |
-| `ARGUS_PORT` | `8100` | Datasette API port |
-| `ARGUS_DASHBOARD_PORT` | `8101` | Dashboard port |
+| `ARGUS_PORT` | `8100` | Dashboard port (datasette runs on port+1) |
 | `GH_TOKEN` | — | GitHub API token |
 
 ## Architecture
@@ -104,11 +103,13 @@ Environment variables:
         ┌─────────┴─────────┐
         ▼                   ▼
 ┌───────────────┐   ┌───────────────┐
-│   Datasette   │   │   Dashboard   │
-│  :8100 (API)  │   │ :8101 (HTML)  │
+│   Dashboard   │   │   Datasette   │
+│  :PORT (HTML) │   │ :PORT+1 (API) │
 └───────────────┘   └───────────────┘
 ```
 
+Default: Dashboard on 8100, Datasette on 8101. Set `ARGUS_PORT` to change base port.
+
 ## Installation
 
 ### Prerequisites

bin/argus

@@ -21,8 +21,7 @@ from typing import Optional
 
 VERSION = "0.1.0"
 DEFAULT_DB_PATH = Path.home() / ".argus" / "argus.db"
-DEFAULT_PORT = 8100
-DEFAULT_DASHBOARD_PORT = 8101
+DEFAULT_PORT = 8100  # Dashboard port; datasette runs on port+1
 
 def get_db_path() -> Path:
     return Path(os.environ.get("ARGUS_DB", DEFAULT_DB_PATH))
@@ -474,31 +473,47 @@ def cmd_escalate_resolve(args) -> None:
 def cmd_serve(args) -> None:
     """Start datasette + dashboard servers."""
     import http.server
-    import threading
     
     db_path = get_db_path()
     dashboard_path = get_dashboard_path()
     
+    # Single port config: dashboard on port, datasette on port+1
     port = args.port or int(os.environ.get("ARGUS_PORT", DEFAULT_PORT))
-    dashboard_port = args.dashboard_port or int(os.environ.get("ARGUS_DASHBOARD_PORT", DEFAULT_DASHBOARD_PORT))
+    datasette_port = port + 1
     
     print(f"Starting Argus servers...")
-    print(f"  Datasette:  http://localhost:{port}")
-    print(f"  Dashboard:  http://localhost:{dashboard_port}")
+    print(f"  Dashboard:  http://localhost:{port}")
+    print(f"  Datasette:  http://localhost:{datasette_port}")
     print()
     
     # Start datasette in background
     datasette_proc = subprocess.Popen(
-        ["datasette", str(db_path), "-p", str(port), "--cors"],
+        ["datasette", str(db_path), "-p", str(datasette_port), "--cors"],
         stdout=subprocess.DEVNULL,
         stderr=subprocess.DEVNULL
     )
     
-    # Start simple HTTP server for dashboard
+    # Custom handler that injects the datasette port into the dashboard
+    class ArgusHandler(http.server.SimpleHTTPRequestHandler):
+        def do_GET(self):
+            if self.path == "/" or self.path == "/index.html":
+                self.send_response(200)
+                self.send_header("Content-type", "text/html")
+                self.end_headers()
+                with open(dashboard_path) as f:
+                    html = f.read()
+                # Inject datasette port config
+                html = html.replace(
+                    "const API_BASE = 'http://localhost:8100'",
+                    f"const API_BASE = 'http://localhost:{datasette_port}'"
+                )
+                self.wfile.write(html.encode())
+            else:
+                super().do_GET()
+    
     os.chdir(dashboard_path.parent)
     
-    handler = http.server.SimpleHTTPRequestHandler
-    with http.server.HTTPServer(("", dashboard_port), handler) as httpd:
+    with http.server.HTTPServer(("", port), ArgusHandler) as httpd:
         try:
             httpd.serve_forever()
         except KeyboardInterrupt:
@@ -579,8 +594,7 @@ def main():
     
     # Serve command
     serve_parser = subparsers.add_parser("serve", help="Start servers")
-    serve_parser.add_argument("--port", type=int, help=f"Datasette port (default: {DEFAULT_PORT})")
-    serve_parser.add_argument("--dashboard-port", type=int, help=f"Dashboard port (default: {DEFAULT_DASHBOARD_PORT})")
+    serve_parser.add_argument("--port", type=int, help=f"Dashboard port (default: {DEFAULT_PORT}); datasette runs on port+1")
     
     args = parser.parse_args()
     

docs/SKILL.md

@@ -69,8 +69,7 @@ argus serve [--port 8100] [--dashboard-port 8101]
 | Variable | Default | Description |
 |----------|---------|-------------|
 | `ARGUS_DB` | `~/.argus/argus.db` | Database path |
-| `ARGUS_PORT` | `8100` | Datasette port |
-| `ARGUS_DASHBOARD_PORT` | `8101` | Dashboard port |
+| `ARGUS_PORT` | `8100` | Dashboard port (datasette on port+1) |
 | `GH_TOKEN` | — | GitHub API token |
 
 ## Workflow

systemd/argus.service

@@ -9,7 +9,6 @@ Restart=on-failure
 RestartSec=5
 Environment=ARGUS_DB=/root/.argus/argus.db
 Environment=ARGUS_PORT=8100
-Environment=ARGUS_DASHBOARD_PORT=8101
 
 [Install]
 WantedBy=multi-user.target