Scaffold matrix-bridge (standards-compliant; pre-Phase 0)

Single-user Matrix -> Claude Code bridge bot, scaffolded from a prior scoping
package (SPEC/DECISIONS/CLAUDE/KICKOFF) folded into the current new-project scheme:
- AGENTS.md (canonical) with core flow, stack, placement table, condensed D1-D10
  decisions, sovereignty constraint, and Phase 0 as the first milestone
- CLAUDE.md -> AGENTS.md relative symlink; ROADMAP.md (Phases 1-4+, falsifiable exits)
- scripts/launch-claude.sh first-draft Mac wrapper (D4); config.example.toml
- canonical deny-by-default .gitignore + Python ignores

No bot code yet, by design: Phase 0 is manual-chain validation (N=3).

README.md

@@ -0,0 +1,31 @@
+# matrix-bridge
+
+A single-user Matrix → Claude Code bridge. Send a message in a project's Matrix room and a
+Claude Code session launches on the Mac in that project's repo, then surfaces to your phone
+via Claude Code Remote Control. The point: make the *trigger* for a coding session portable
+without moving execution off the Mac.
+
+Runs as a small **matrix-nio** bot in a Docker container on a DGX Spark; a zsh wrapper on the
+Mac (`scripts/launch-claude.sh`) is the only piece that knows the Mac's environment. Routing
+is deterministic in v1 — the room you message in decides the repo (an explicit config map).
+
+> Status: **scaffolded, pre–Phase 0.** No bot code yet. See `AGENTS.md` → `## Current state`
+> for the active milestone and `ROADMAP.md` for the phase plan.
+
+## How it works (v1)
+
+```
+Matrix message in a project room
+  → bot on the Spark maps room → repo
+  → SSHes to the Mac, runs scripts/launch-claude.sh <repo_dir> <message>
+  → wrapper cd's into the repo and launches `claude`
+  → Remote Control notifies the phone; you drive the session there
+```
+
+## Setup
+
+_TODO — filled in as Phase 0 is proven:_ Matrix onboarding (Element + the existing Synapse
+homeserver, a bot user), the Mac wrapper, passwordless SSH from the Spark to the Mac, and the
+first room→repo mapping. Copy `config.example.toml` to `config.toml` (gitignored) and fill in
+real room IDs and repo paths. The original scoping docs (SPEC / DECISIONS / KICKOFF) hold the
+full background.