fix(fleet): enforce exact comms authority (#787)

packages/mosaic/framework/defaults/TOOLS.md

@@ -5,20 +5,20 @@ Tool suites live at `~/.config/mosaic/tools/<suite>/`. This is the index only.
 read it (or the relevant service guide) when your task actually touches that service.
 Project-specific tooling belongs in the project's `AGENTS.md`, not here.
 
-## ⚡ Most-used fleet tools (reach for these FIRST — don't hand-roll)
+## Most-used fleet tools (reach for these first)
 
-You are a Mosaic fleet agent. These cover the highest-frequency cross-agent and git-provider
-tasks — use them before improvising with raw `tmux send-keys`, raw `tea`/`gh`/`glab`, or `curl`.
+<!-- fleet-comms-contract: 1 -->
 
-**1. Message another agent** → `tools/tmux/agent-send.sh` (NOT raw `tmux send-keys`):
+You are a Mosaic fleet agent. Use the runtime-composed **Fleet Comms — authoritative exact targets**
+section for inter-agent messaging. It renders your authoritative local host, exact agent/session, resolved
+tmux socket, installed helper path, generation, and one executable command per known peer.
 
-```bash
-tools/tmux/agent-send.sh -s <target-session> -m "message"   # or -f <file> to send a file's contents
-```
+Select only a peer row rendered for your exact roster identity. Never invent, substitute, or fuzzy-match
+a host, session, socket, SSH destination, or helper path. If a peer is absent, stop and run the exact
+self-scoped discovery command shown in that composed section; report the peer as unknown if it remains
+absent. Do not use raw `tmux send-keys` for fleet messaging.
 
-The coordinator session is `mos-claude` — send status, findings, and questions there.
-
-**2. Issues / PRs / milestones** → `tools/git/*.sh` wrappers (before raw `tea`/`gh`/`glab`):
+**Issues / PRs / milestones** → `tools/git/*.sh` wrappers (before raw `tea`/`gh`/`glab`):
 
 ```bash
 tools/git/pr-create.sh ...   tools/git/issue-create.sh ...   tools/git/pr-merge.sh ...