release: bump firmware version to 0.5.0

docs/API.md

@@ -19,7 +19,7 @@ All documented endpoints are local-first and must continue to work without inter
 Current firmware version:
 
 ```text
-0.4.0
+0.5.0
 ```
 
 ## Current Endpoints
@@ -91,7 +91,7 @@ Returns a lightweight liveness response for dashboards and service tools.
   "ok": true,
   "api_version": "v1",
   "firmware_name": "overland-controller",
-  "firmware_version": "0.4.0",
+  "firmware_version": "0.5.0",
   "uptime_seconds": 123,
   "network": {
     "ap_enabled": true,
@@ -120,7 +120,7 @@ Returns API and feature discovery data for clients.
   "ok": true,
   "api_version": "v1",
   "firmware_name": "overland-controller",
-  "firmware_version": "0.4.0",
+  "firmware_version": "0.5.0",
   "endpoints": [
     "GET /api/v1/status",
     "POST /api/v1/relay/set"
@@ -319,7 +319,7 @@ The AP remains enabled even when STA WiFi is configured or connected.
 ```json
 {
   "firmware_name": "overland-controller",
-  "firmware_version": "0.4.0",
+  "firmware_version": "0.5.0",
   "build_date": "Jun  7 2026",
   "build_time": "12:00:00",
   "uptime_seconds": 123
@@ -472,7 +472,7 @@ Important: export includes saved WiFi passwords so the backup can be restored. T
   "ok": true,
   "api_version": "v1",
   "firmware_name": "overland-controller",
-  "firmware_version": "0.4.0",
+  "firmware_version": "0.5.0",
   "config": {
     "device_name": "Overland Controller",
     "temperature_sensor_count": 4,