feat(hosts): wire Droid (Factory CLI) and the Pi coding agent into graft init

[bitnom]

Adds the two agents graft couldn't yet wire to graft init:

• Droid (Factory CLI): an AGENTS.md instruction section (Droid reads AGENTS.md per Factory's docs) plus a repo-level .factory/mcp.json MCP registration — the committed, team-shared level of droid's user/folder/project trio (MCP docs), matching how cursor/gemini/kiro are wired. Detected via ~/.factory or a repo .factory dir. Selecting droid alongside the generic agents row runs two identical AGENTS.md upserts — the fenced section is still written exactly once.
• Pi coding agent: a graft-owned skill at .pi/skills/graft/SKILL.md (pi discovers .pi/skills/ from the cwd upward). Pi's own README documents a no-MCP philosophy, so wiring is deliberately skill + AGENTS.md only — no MCP registration — and the graft binary on PATH stays the integration surface. Detected via ~/.pi or a repo .pi dir.

Retraction needs no new code: both targets derive from the same registries init writes through, so graft uninstall removes the skill file and the .factory/mcp.json key for free.

Evidence

• Full suite: 1224 passed / 0 failed.
• New tests: droid detection (home + repo probes), AGENTS.md single-section invariant with the shared-file rows, pi skill file shape (name: graft frontmatter), pi MCP absence, .factory/mcp.json merge + re-run convergence, registry id list.

[trailhq-graft]

🌱 graft blast radius

1 area changed → 6 areas can be affected. 16 dependent symbols, depth 2.
Tests: 1 area updated its tests.
Tag: @anirudhkumar-nanonets — 7 of 7 areas · @shhdwi — 5 of 7 areas

flowchart TB
  A0(("CLI Wiring<br/>6 symbols"))
  A1(("Host Integrations<br/>4 symbols"))
  A2(("Claude Initialization<br/>2 symbols"))
  A3(("Brain Connectivity<br/>2 symbols"))
  A4(("MCP Server<br/>1 symbol"))
  AX(("1 smaller area<br/>1 symbol"))
  classDef reached fill:#D9EDF3,stroke:#3AA7C9,stroke-width:1.5px,color:#0E313C;
  class A0,A1,A2,A3,A4 reached;
  classDef tail fill:#EEF2F3,stroke:#9AA4A9,stroke-width:1px,color:#3A4247;
  class AX tail;

Loading

Can be affected	Symbols	Nearest hop	Reached from
CLI Wiring	6	src/cli.ts:L1088-L1173 wireTarget — calls, depth 1	Host Configuration
Host Integrations	4	src/hosts/antigravity.ts:L1-L47 antigravity.ts — imports, depth 2	Host Configuration
Claude Initialization	2	src/claude/hooks.ts:L1-L463 hooks.ts — imports, depth 2	Host Configuration
Brain Connectivity	2	src/brain/wire.ts:L1-L148 wire.ts — imports, depth 1	Host Configuration
MCP Server	1	src/mcp/server.ts:L1-L152 server.ts — imports, depth 2	Host Configuration
Telemetry Tracking	1	src/telemetry/track.ts:L1-L156 track.ts — imports, depth 2	Host Configuration

Who knows this code — 2 people across 7 areas

Area	Who knows it
Host Configuration · changed	@shhdwi — 8 commits, last 1mo ago · @anirudhkumar-nanonets — 6 commits, last 4d ago
CLI Wiring · affected	@anirudhkumar-nanonets — 40 commits, last 4d ago · @shhdwi — 23 commits, last 1mo ago
Host Integrations · affected	@shhdwi — 5 commits, last 1mo ago · @anirudhkumar-nanonets — 2 commits, last 13d ago
Claude Initialization · affected	@anirudhkumar-nanonets — 17 commits, last 12d ago · @shhdwi — 11 commits, last 1mo ago
Brain Connectivity · affected	@anirudhkumar-nanonets — 1 commit, last 4d ago
MCP Server · affected	@anirudhkumar-nanonets — 5 commits, last 13d ago · @shhdwi — 2 commits, last 2mo ago
Telemetry Tracking · affected	@anirudhkumar-nanonets — 2 commits, last 14d ago

Ownership is git history over each area's own files, weighted towards recent work (120-day half-life). Merge commits and bots are dropped, and you are dropped from your own PR. A name with no @ has no GitHub handle in its commit email — tag them by hand, or add a .mailmap entry. A suggestion from history, not a CODEOWNERS rule.

All 16 dependent symbols, grouped by area

CLI Wiring — 6 symbols in 4 files

• src/cli.ts:L1088-L1173 — wireTarget (calls, depth 1)
  1094: plan: ReturnType<typeof planInit>;
• src/cli.ts:L1-L1407 — cli.ts (calls, depth 1)
  18: import { runHostsInit } from "./hosts/init.js";
• src/upkeep-run.ts:L42-L51 — rewriteWiring (calls, depth 1)
  50: runHostsInit(repo, { agents: others, global: opts.global, mcp: opts.mcp, hooks: opts.hooks });
• src/upkeep.ts:L1-L333 — upkeep.ts (imports, depth 1)
  11: * 2. **Wiring staleness** — `graft init` copies hooks, shims, skill text and
• src/cli-picker.ts:L1-L385 — cli-picker.ts (imports, depth 2)
  2: * `graft init`'s agent picker and `--dry-run` plan printer.
• src/upkeep-run.ts:L1-L82 — upkeep-run.ts (imports, depth 2)
  9: import { runHostsInit } from './hosts/init.js';

Host Integrations — 4 symbols in 4 files

• src/hosts/antigravity.ts:L1-L47 — antigravity.ts (imports, depth 2)
  20: function skillPath(home: string): string {
• src/hosts/claude-global.ts:L1-L126 — claude-global.ts (imports, depth 2)
  5: * Why this exists. Everything `graft init` writes for Claude Code lands *in* the
• src/hosts/codex-hooks.ts:L1-L91 — codex-hooks.ts (imports, depth 2)
  62: const targets = hookTargets(home);
• src/hosts/cursor-hooks.ts:L1-L110 — cursor-hooks.ts (imports, depth 2)
  29: import type { PlannedWrite } from './plan.js';

Claude Initialization — 2 symbols in 2 files

• src/claude/hooks.ts:L1-L463 — hooks.ts (imports, depth 2)
  50: * A query now brings the graph up to date first, so `graft init` raises the
• src/claude/init.ts:L1-L105 — init.ts (imports, depth 2)
  86: const skillPath = skill;

Brain Connectivity — 2 symbols in 2 files

• src/brain/wire.ts:L1-L148 — wire.ts (imports, depth 1)
  12: * instruction block: instructions are static and rewritten by `init`, rules
• src/brain/connect.ts:L1-L111 — connect.ts (imports, depth 2)

MCP Server — 1 symbol in 1 file

• src/mcp/server.ts:L1-L152 — server.ts (imports, depth 2)
  74: // refreshes rule files an older `graft init` wrote, and kicks off the cached

Telemetry Tracking — 1 symbol in 1 file

• src/telemetry/track.ts:L1-L156 — track.ts (imports, depth 2)

Test signal per changed area — 1 ✓

Reached = a node under a test path has a resolved edge into the changed symbol. It undercounts anything called indirectly — through a CLI, a spawned process or a dynamic import — so read a low ratio as “look here”, never as a coverage gate.

• ✓ Host Configuration — 3 of 7 reached · 2 test files changed here: test/hosts-init.test.ts, test/hosts-registry.test.ts
  • not reached: installProjectAgentSkill, projectAgentSkillTargets, skillPath, targets

9 test suites also reference this code

12 symbols, kept out of the diagram and the table so they cannot crowd out the areas a reviewer has to look at.

• test/claude-init.test.ts
• test/cli-picker.test.ts
• test/hosts-antigravity.test.ts
• test/hosts-claude-global.test.ts
• test/hosts-cursor-hooks.test.ts
• test/hosts-plan.test.ts
• test/hosts-retract.test.ts
• test/upkeep-hooks.test.ts
• test/upkeep.test.ts

⚠️ 1 changed file not in the graph (CHANGELOG.md) — no parser claims the extension, or the index predates the file.

_{graft blast · origin/main...HEAD · depth 2 · 11 changed files}

Open the interactive graph → — click an area to see its dependent symbols at file:line.

[bitnom]

Intent to restructure the init rows (follow-up). This PR adds project-agents additively, but the end-state we want is a restructure: project-agents becomes the canonical instructions+skill row, vendor rows slim down to their genuinely vendor-specific writes (droid → .factory/mcp.json only; pi absorbed into project-agents), and the agents row reduces to its machine-wide Codex pieces. Today's rows mix three axes in one bundle (shared conventions, vendor config, machine-wide hooks) and the picker can't express "standard files only, nothing outside this repo" as a result. Deferred from this PR so the row-semantics change gets its own review — this PR's additive row is a strict improvement on its own.