feat(coding-agent): add Android/Termux support

- Make @mariozechner/clipboard an optional dependency
- Lazy-load clipboard module with graceful fallback
- Add Termux clipboard support via termux-clipboard-set
- Skip image clipboard on Termux (not supported)

fixes #1164

packages/coding-agent/package.json

@@ -39,7 +39,6 @@
 		"prepublishOnly": "npm run clean && npm run build"
 	},
 	"dependencies": {
-		"@mariozechner/clipboard": "^0.3.2",
 		"@mariozechner/jiti": "^2.6.2",
 		"@mariozechner/pi-agent-core": "^0.50.9",
 		"@mariozechner/pi-ai": "^0.50.9",
@@ -56,6 +55,9 @@
 		"proper-lockfile": "^4.1.2",
 		"yaml": "^2.8.2"
 	},
+	"optionalDependencies": {
+		"@mariozechner/clipboard": "^0.3.2"
+	},
 	"devDependencies": {
 		"@types/diff": "^7.0.2",
 		"@types/ms": "^2.1.0",