docs: finalize skill install hints

skills/bird/SKILL.md

@@ -1,7 +1,7 @@
 ---
 name: bird
 description: X/Twitter CLI for reading, searching, and posting via cookies or Sweetistics.
-metadata: {"clawdis":{"requires":{"bins":["bird"]}}}
+metadata: {"clawdis":{"requires":{"bins":["bird"]},"install":[{"id":"pnpm-build","kind":"shell","command":"if [ ! -d ~/Projects/bird ]; then git clone https://github.com/steipete/bird.git ~/Projects/bird; fi && cd ~/Projects/bird && pnpm install && pnpm run binary","bins":["bird"],"label":"Clone + build bird (pnpm)"}]}}
 ---
 
 # bird

skills/eightctl/SKILL.md

@@ -1,7 +1,7 @@
 ---
 name: eightctl
 description: Control Eight Sleep pods (status, temperature, alarms, schedules).
-metadata: {"clawdis":{"requires":{"bins":["eightctl"]}}}
+metadata: {"clawdis":{"requires":{"bins":["eightctl"]},"install":[{"id":"go","kind":"go","module":"github.com/steipete/eightctl/cmd/eightctl@latest","bins":["eightctl"],"label":"Install eightctl (go)"}]}}
 ---
 
 # eightctl

skills/imsg/SKILL.md

@@ -1,7 +1,7 @@
 ---
 name: imsg
 description: iMessage/SMS CLI for listing chats, history, watch, and sending.
-metadata: {"clawdis":{"requires":{"bins":["imsg"]}}}
+metadata: {"clawdis":{"requires":{"bins":["imsg"]},"install":[{"id":"go","kind":"go","module":"github.com/steipete/imsg/cmd/imsg@latest","bins":["imsg"],"label":"Install imsg (go)"}]}}
 ---
 
 # imsg

skills/qmd/SKILL.md

@@ -1,7 +1,7 @@
 ---
 name: qmd
 description: Local search/indexing CLI (BM25 + vectors + rerank) with MCP mode.
-metadata: {"clawdis":{"requires":{"bins":["qmd"]}}}
+metadata: {"clawdis":{"requires":{"bins":["qmd"]},"install":[{"id":"node","kind":"node","package":"https://github.com/tobi/qmd","bins":["qmd"],"label":"Install qmd (node)"}]}}
 ---
 
 # qmd