#23673: docs(imessage): update cliPath to Homebrew path for Apple Silicon

## Summary - **Problem:** The iMessage channel docs showed `/usr/local/bin/imsg` as the `cliPath`, which is the legacy Intel Homebrew path. On Apple Silicon Macs (M1/M2/M3+) — now the majority of new Mac hardware — Homebrew installs to `/opt/homebrew/bin`, causing "binary not found" failures for users following the docs. - **Why it matters:** First-time setup on Apple Silicon breaks silently if the user copies the config verbatim. - **What changed:** Updated one line in `docs/channels/imessage.md`: `cliPath` example from `/usr/local/bin/imsg` → `/opt/homebrew/bin/imsg`. - **What did NOT change:** No runtime code, no config schema, no behavior. Intel Mac users can still override to `/usr/local/bin/imsg` manually. ## Change Type (select all) - [ ] Bug fix - [ ] Feature - [ ] Refactor - [X] Docs - [ ] Security hardening - [ ] Chore/infra ## Scope (select all touched areas) - [ ] Gateway / orchestration - [ ] Skills / tool execution - [ ] Auth / tokens - [ ] Memory / storage - [X] Integrations - [ ] API / contracts - [ ] UI / DX - [ ] CI/CD / infra ## Linked Issue/PR - Closes # - Related # ## User-visible / Behavior Changes Users following `docs/channels/imessage.md` on Apple Silicon Macs will now have the correct default `cliPath` for their Homebrew installation. Intel Mac users are unaffected (they set `cliPath: "/usr/local/bin/imsg"` manually if needed). ## Security Impact (required) - New permissions/capabilities? No - Secrets/tokens handling changed? No - New/changed network calls? No - Command/tool execution surface changed? No - Data access scope changed? No ## Repro + Verification ### Environment - OS: macOS (Apple Silicon — M1/M2/M3) - Runtime/container: Node / native - Model/provider: N/A (docs-only) - Integration/channel: iMessage - Relevant config (redacted): ```yaml channels: imessage: enabled: true cliPath: "/opt/homebrew/bin/imsg" <!-- greptile_comment --> <h3>Greptile Summary</h3> Updated `cliPath` example in iMessage channel docs from `/usr/local/bin/imsg` (Intel Homebrew path) to `/opt/homebrew/bin/imsg` (Apple Silicon Homebrew path). - Aligns documentation with current Mac hardware (M1/M2/M3 now majority) - Prevents "binary not found" errors for users following docs verbatim on Apple Silicon - Intel Mac users can still manually override to `/usr/local/bin/imsg` if needed - No runtime code, config schema, or behavior changes <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with no risk - Documentation-only change updating a single file path example to match current Apple Silicon Homebrew standard. No code, tests, or runtime behavior affected. The change is factually correct and improves user experience. - No files require special attention _{Last reviewed commit: fb36641} <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->