feat(new-setup-2): add per-channel bundled install scripts

Twelve idempotent install scripts matching install-telegram.sh's shape,
one per channel in /new-setup-2's pick list (except Emacs, which uses
a git-merge install flow). Each bundles preflight + fetch + copy +
register + pnpm install + build so a single allowlisted bash call can
replace a chain of permission prompts. Linear's also patches
chat-sdk-bridge.ts for catchAll forwarding; Matrix's runs the
post-install ESM-extension dist patch; WhatsApp-native's covers the
deterministic install portion only — QR/pairing auth still lives in
/add-whatsapp.

Scripts only; new-setup-2/SKILL.md integration deferred pending a
decision on whether to generalize the set-env pattern from 712a0e1
across the Chat SDK channels (each /add-<channel>/SKILL.md's
Credentials section has a similar unapprovable shell chain).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

setup/install-linear.sh

@@ -0,0 +1,95 @@
+#!/usr/bin/env bash
+# Setup helper: install-linear — bundles the preflight + install commands
+# from the /add-linear skill into one idempotent script so /new-setup-2 can
+# run them programmatically before continuing to credentials.
+#
+# Copies the Linear adapter in from the `channels` branch; appends the
+# self-registration import; patches src/channels/chat-sdk-bridge.ts to add
+# catch-all forwarding (Linear OAuth apps can't be @-mentioned, so the
+# onNewMention handler never fires — the bridge needs a catchAll path);
+# installs the pinned @chat-adapter/linear package; builds. All steps are
+# safe to re-run.
+#
+# Note: the bridge patch's onNewMessage handler passes `false` for isMention
+# (current trunk signature requires the arg). The /add-linear SKILL's
+# snippet omits the arg — this script uses the full signature so TypeScript
+# builds cleanly.
+set -euo pipefail
+
+PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$PROJECT_ROOT"
+
+echo "=== NANOCLAW SETUP: INSTALL_LINEAR ==="
+
+needs_install=false
+[[ -f src/channels/linear.ts ]] || needs_install=true
+grep -q "import './linear.js';" src/channels/index.ts || needs_install=true
+grep -q '"@chat-adapter/linear"' package.json || needs_install=true
+[[ -d node_modules/@chat-adapter/linear ]] || needs_install=true
+grep -q 'catchAll' src/channels/chat-sdk-bridge.ts || needs_install=true
+
+if ! $needs_install; then
+  echo "STATUS: already-installed"
+  echo "=== END ==="
+  exit 0
+fi
+
+echo "STEP: fetch-channels-branch"
+git fetch origin channels
+
+echo "STEP: copy-files"
+git show origin/channels:src/channels/linear.ts > src/channels/linear.ts
+
+echo "STEP: register-import"
+if ! grep -q "import './linear.js';" src/channels/index.ts; then
+  printf "import './linear.js';\n" >> src/channels/index.ts
+fi
+
+echo "STEP: patch-bridge-catchall-field"
+if ! grep -q 'catchAll?: boolean;' src/channels/chat-sdk-bridge.ts; then
+  awk '
+    /^export interface ChatSdkBridgeConfig \{/ { in_iface = 1 }
+    in_iface && /^\}/ && !inserted {
+      print "  /**"
+      print "   * Forward ALL messages in unsubscribed threads, not just @-mentions."
+      print "   * Use for platforms where the bot identity can'\''t be @-mentioned (e.g."
+      print "   * Linear OAuth apps). The thread is auto-subscribed on first message."
+      print "   */"
+      print "  catchAll?: boolean;"
+      inserted = 1
+      in_iface = 0
+    }
+    { print }
+  ' src/channels/chat-sdk-bridge.ts > src/channels/chat-sdk-bridge.ts.tmp \
+    && mv src/channels/chat-sdk-bridge.ts.tmp src/channels/chat-sdk-bridge.ts
+fi
+
+echo "STEP: patch-bridge-catchall-handler"
+if ! grep -q 'if (config.catchAll) {' src/channels/chat-sdk-bridge.ts; then
+  awk '
+    /      \/\/ DMs — apply engage rules too/ && !inserted {
+      print "      // Catch-all for platforms where @-mention isn'\''t possible (e.g. Linear"
+      print "      // OAuth apps). Forward every unsubscribed message and auto-subscribe."
+      print "      if (config.catchAll) {"
+      print "        chat.onNewMessage(/.*/, async (thread, message) => {"
+      print "          const channelId = adapter.channelIdFromThreadId(thread.id);"
+      print "          await setupConfig.onInbound(channelId, thread.id, await messageToInbound(message, false));"
+      print "          await thread.subscribe();"
+      print "        });"
+      print "      }"
+      print ""
+      inserted = 1
+    }
+    { print }
+  ' src/channels/chat-sdk-bridge.ts > src/channels/chat-sdk-bridge.ts.tmp \
+    && mv src/channels/chat-sdk-bridge.ts.tmp src/channels/chat-sdk-bridge.ts
+fi
+
+echo "STEP: pnpm-install"
+pnpm install @chat-adapter/linear@4.26.0
+
+echo "STEP: pnpm-build"
+pnpm run build
+
+echo "STATUS: installed"
+echo "=== END ==="