Items #2 (clippy sweep) and #1 (close the CI gap) from the follow-up
list, as one PR — the lint fixes and the gate that enforces them belong
together so CI is self-consistent.

## Why
The only Rust CI was CodeQL in build-mode `none` (**buildless**) —
nothing compiled or tested `robot-repo-automaton` / `shared-context` /
`dashboard`. That's exactly how the non-compiling content-match path
reached `main` before #299 fixed it. This closes that gap.

## The gate — `.github/workflows/rust.yml`
Per-crate matrix (modeled on `e2e.yml`: SHA-pinned checkout,
`permissions: contents: read`, SPDX header):
- `cargo build --all-targets`
- `cargo test`
- `cargo clippy --all-targets -- -D warnings` *(blocking)*
- `cargo fmt --check` *(informational, `continue-on-error`)* — there's
~180 hunks of **pre-existing** formatting drift; gating it would mean a
giant reformat that buries this change, so it's surfaced but not yet
enforced. A dedicated `cargo fmt` pass can flip it to blocking later.

## Clippy fixes (to make the gate green)
| File | Finding | Fix |
|---|---|---|
| `fixer.rs` | `.replace("hyperpolymath", "hyperpolymath")` | no-op —
removed |
| `registry_guard.rs` | manual `splitn(2, '/')` | `split_once('/')` |
| `exclusion_registry.rs` | `from_str` shadows `FromStr` | rename
inherent `from_str` → `parse` (matches `Catalog::parse`; 2 internal call
sites) |
| `exclusion_registry.rs` | `.ok()` + `if let Some` | `if let Ok(..)` |
| `hypatia.rs`, `main.rs` | `&PathBuf` arg | `&Path` |
| `Cargo.toml` ×2 | `toml = "1.1.2+spec-1.1.0"` | drop ignored `+spec`
build-metadata (resolution-neutral; silences cargo warning) |
| `benches/fleet_benchmarks.rs` | deprecated `criterion::black_box` |
import `std::hint::black_box` (one import swap covers all call sites) |

## Verification
All three crates: **clippy `-D warnings` clean**, build clean. Tests:
**101** (robot-repo-automaton) + **84** (shared-context) pass. Locally
simulated the full matrix (build + test + clippy) green per crate;
`rust.yml` parses as valid YAML.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

https://claude.ai/code/session_01RozeeLxpJsd3WWFngaZWz3

---
_Generated by [Claude
Code](https://claude.ai/code/session_01RozeeLxpJsd3WWFngaZWz3)_

---------

Co-authored-by: Claude <noreply@anthropic.com>