feat(telegram,discord): migrate to plugin userConfig secrets

Closes H1 #3617646 via the proper path — plugin userConfig with
sensitive: true routes tokens to keychain (macOS) or .credentials.json
0600 (elsewhere) instead of world-readable .env files.

Requires claude-cli-internal#23383 (PLUGIN_OPTIONS ungate + per-server
sensitive split).

Changes per plugin:
  - plugin.json: add userConfig.{PLATFORM}_BOT_TOKEN with sensitive: true
  - .mcp.json: add env block with ${user_config.{PLATFORM}_BOT_TOKEN}
  - server.ts: update comment + error message to point to
    /plugin reconfigure instead of .env file

The .env read loop stays as a legacy fallback for existing users —
process.env wins (injected value takes precedence), so no migration
forced. New users get prompted at enable time via CC's built-in dialog;
token lands in keychain, never touches settings.json.

/telegram:configure and /discord:configure skills are NOT removed in this
PR — they still work for the legacy .env path. Follow-up: repurpose or
remove after a grace period once cli#23383 is released.

🏠 Remote-Dev: homespace

external_plugins/discord/.claude-plugin/plugin.json

@@ -1,11 +1,20 @@
 {
   "name": "discord",
-  "description": "Discord channel for Claude Code \u2014 messaging bridge with built-in access control. Manage pairing, allowlists, and policy via /discord:access.",
-  "version": "0.0.1",
+  "description": "Discord channel for Claude Code — messaging bridge with built-in access control. Manage pairing, allowlists, and policy via /discord:access.",
+  "version": "0.0.2",
   "keywords": [
     "discord",
     "messaging",
     "channel",
     "mcp"
-  ]
+  ],
+  "userConfig": {
+    "DISCORD_BOT_TOKEN": {
+      "type": "string",
+      "title": "Bot Token",
+      "description": "Bot token from the Discord Developer Portal. Stored in keychain (macOS) or ~/.claude/.credentials.json with 0600 permissions elsewhere. Never written to settings.json.",
+      "required": true,
+      "sensitive": true
+    }
+  }
 }

external_plugins/discord/.mcp.json

@@ -2,7 +2,10 @@
   "mcpServers": {
     "discord": {
       "command": "bun",
-      "args": ["run", "--cwd", "${CLAUDE_PLUGIN_ROOT}", "--shell=bun", "--silent", "start"]
+      "args": ["run", "--cwd", "${CLAUDE_PLUGIN_ROOT}", "--shell=bun", "--silent", "start"],
+      "env": {
+        "DISCORD_BOT_TOKEN": "${user_config.DISCORD_BOT_TOKEN}"
+      }
     }
   }
 }

external_plugins/discord/server.ts

@@ -34,10 +34,12 @@ const ACCESS_FILE = join(STATE_DIR, 'access.json')
 const APPROVED_DIR = join(STATE_DIR, 'approved')
 const ENV_FILE = join(STATE_DIR, '.env')
 
-// Load ~/.claude/channels/discord/.env into process.env. Real env wins.
-// Plugin-spawned servers don't get an env block — this is where the token lives.
+// Token is injected via ${user_config.DISCORD_BOT_TOKEN} from .mcp.json —
+// prompted at enable time, stored in keychain (macOS) or .credentials.json 0600
+// elsewhere. The .env file below is a legacy fallback for users configured
+// before H1 #3617646 — real env wins, so the injected value takes precedence.
 try {
-  // Token is a credential — lock to owner. No-op on Windows (would need ACLs).
+  // Defensive chmod for legacy .env files (no-op on Windows).
   chmodSync(ENV_FILE, 0o600)
   for (const line of readFileSync(ENV_FILE, 'utf8').split('\n')) {
     const m = line.match(/^(\w+)=(.*)$/)
@@ -51,8 +53,8 @@ const STATIC = process.env.DISCORD_ACCESS_MODE === 'static'
 if (!TOKEN) {
   process.stderr.write(
     `discord channel: DISCORD_BOT_TOKEN required\n` +
-    `  set in ${ENV_FILE}\n` +
-    `  format: DISCORD_BOT_TOKEN=MTIz...\n`,
+    `  configure via: /plugin reconfigure discord\n` +
+    `  (stored in keychain/credentials.json, not settings.json)\n`,
   )
   process.exit(1)
 }

external_plugins/telegram/.claude-plugin/plugin.json

@@ -1,11 +1,20 @@
 {
   "name": "telegram",
-  "description": "Telegram channel for Claude Code \u2014 messaging bridge with built-in access control. Manage pairing, allowlists, and policy via /telegram:access.",
-  "version": "0.0.1",
+  "description": "Telegram channel for Claude Code — messaging bridge with built-in access control. Manage pairing, allowlists, and policy via /telegram:access.",
+  "version": "0.0.2",
   "keywords": [
     "telegram",
     "messaging",
     "channel",
     "mcp"
-  ]
+  ],
+  "userConfig": {
+    "TELEGRAM_BOT_TOKEN": {
+      "type": "string",
+      "title": "Bot Token",
+      "description": "Bot token from @BotFather — format is 123456789:AAH... Stored in keychain (macOS) or ~/.claude/.credentials.json with 0600 permissions elsewhere. Never written to settings.json.",
+      "required": true,
+      "sensitive": true
+    }
+  }
 }

external_plugins/telegram/.mcp.json

@@ -2,7 +2,10 @@
   "mcpServers": {
     "telegram": {
       "command": "bun",
-      "args": ["run", "--cwd", "${CLAUDE_PLUGIN_ROOT}", "--shell=bun", "--silent", "start"]
+      "args": ["run", "--cwd", "${CLAUDE_PLUGIN_ROOT}", "--shell=bun", "--silent", "start"],
+      "env": {
+        "TELEGRAM_BOT_TOKEN": "${user_config.TELEGRAM_BOT_TOKEN}"
+      }
     }
   }
 }

external_plugins/telegram/server.ts

@@ -27,10 +27,12 @@ const ACCESS_FILE = join(STATE_DIR, 'access.json')
 const APPROVED_DIR = join(STATE_DIR, 'approved')
 const ENV_FILE = join(STATE_DIR, '.env')
 
-// Load ~/.claude/channels/telegram/.env into process.env. Real env wins.
-// Plugin-spawned servers don't get an env block — this is where the token lives.
+// Token is injected via ${user_config.TELEGRAM_BOT_TOKEN} from .mcp.json —
+// prompted at enable time, stored in keychain (macOS) or .credentials.json 0600
+// elsewhere. The .env file below is a legacy fallback for users configured
+// before H1 #3617646 — real env wins, so the injected value takes precedence.
 try {
-  // Token is a credential — lock to owner. No-op on Windows (would need ACLs).
+  // Defensive chmod for legacy .env files (no-op on Windows).
   chmodSync(ENV_FILE, 0o600)
   for (const line of readFileSync(ENV_FILE, 'utf8').split('\n')) {
     const m = line.match(/^(\w+)=(.*)$/)
@@ -44,8 +46,8 @@ const STATIC = process.env.TELEGRAM_ACCESS_MODE === 'static'
 if (!TOKEN) {
   process.stderr.write(
     `telegram channel: TELEGRAM_BOT_TOKEN required\n` +
-    `  set in ${ENV_FILE}\n` +
-    `  format: TELEGRAM_BOT_TOKEN=123456789:AAH...\n`,
+    `  configure via: /plugin reconfigure telegram\n` +
+    `  (stored in keychain/credentials.json, not settings.json)\n`,
   )
   process.exit(1)
 }