showcase: add Linear CLI and Beeper CLI

- @NessZerra Linear CLI - manage Linear issues from terminal, works with Claude Code/Clawdbot
- @jules Beeper CLI - read/send/archive messages via Beeper Desktop MCP API

docs/start/showcase.md

@@ -146,6 +146,19 @@ Full setup walkthrough (28m) by VelvetShark.
 
   14+ agents under one gateway with Opus 4.5 orchestrator delegating to Codex workers. Comprehensive [technical write-up](https://github.com/adam91holt/orchestrated-ai-articles) covering the Dream Team roster, model selection, sandboxing, webhooks, heartbeats, and delegation flows. [Clawdspace](https://github.com/adam91holt/clawdspace) for agent sandboxing. [Blog post](https://adams-ai-journey.ghost.io/2026-the-year-of-the-orchestrator/).
 </Card>
+
+<Card title="Linear CLI" icon="terminal" href="https://github.com/Finesssee/linear-cli">
+  **@NessZerra** • `devtools` `linear` `cli` `issues`
+
+  CLI for Linear that integrates with agentic workflows (Claude Code, Clawdbot). Manage issues, projects, and workflows from the terminal. First external PR merged!
+</Card>
+
+<Card title="Beeper CLI" icon="message" href="https://github.com/blqke/beepcli">
+  **@jules** • `messaging` `beeper` `cli` `automation`
+
+  Read, send, and archive messages via Beeper Desktop. Uses Beeper local MCP API so agents can manage all your chats (iMessage, WhatsApp, etc.) in one place.
+</Card>
+
 </CardGroup>
 
 ## 🤖 Automation & Workflows