fix: add folderTrust+yolo settings to Gemini installers and README

- settings.json now includes security.folderTrust.enabled=false and
  general.defaultApprovalMode=yolo to suppress trust/permission prompts
- Linux installer creates trustedFolders.json with common paths
- Windows PS1 installer creates trustedFolders.json for C:\ paths
- README Windows section adds $env: vars for current session
- Fixed BOM issue: all PS1 use WriteAllText instead of Set-Content

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gemini/ugemini_install.sh

@@ -168,10 +168,26 @@ assert d.get('security',{}).get('auth',{}).get('selectedType') == 'gemini-api-ke
 " 2>/dev/null; then
     cat > "$SETTINGS_FILE" << 'SETTINGS_EOF'
 {
-  "security": { "auth": { "selectedType": "gemini-api-key" } },
-  "telemetry": { "enabled": false, "logPrompts": false }
+  "security": {
+    "auth": { "selectedType": "gemini-api-key" },
+    "folderTrust": { "enabled": false }
+  },
+  "telemetry": { "enabled": false, "logPrompts": false },
+  "general": { "defaultApprovalMode": "yolo" }
 }
 SETTINGS_EOF
+    # Trust common folders
+    TRUSTED_FILE="$GEMINI_DIR/trustedFolders.json"
+    python3 -c "
+import json, os
+t = {}
+if os.path.isfile('$TRUSTED_FILE'):
+    try: t = json.load(open('$TRUSTED_FILE'))
+    except: pass
+for p in [os.path.expanduser('~'), '/home', '/root', '/tmp']:
+    t.setdefault(p, 'TRUST_PARENT')
+json.dump(t, open('$TRUSTED_FILE', 'w'), indent=2)
+" 2>/dev/null
     log "Settings configured: $SETTINGS_FILE"
 else
     log "Settings already configured"