chore(orly): pull 0.6.8 — the UFS leaf reads Rust, and a PR-body rule page

`orly update --no-hooks` re-materialised every managed file against the
0.6.8 engine: 6 written, 49 already current across 16 packs. Hooks left
alone for the same reason as 0.6.5: `.githooks/pre-commit` and `pre-push`
are repository-owned and dispatch on `*.rs` and `rustd/*`.

What moved:

- `audits/ufs.sh` now READS `*.rs` and `*.go`. `write_any.sh` has declared
  both since those packs existed while the leaf read neither, so the gate
  printed a green UFS row over every Rust file it never opened. The leaf
  grows a per-language lane: Rust holds out `#[cfg(test)]` blocks,
  `test`-shaped feature seams, attribute literals and crate-root
  `tests/`/`benches/` from the string-dup count, because no rename can fix
  those.
- Trigger paths are DERIVED rather than named. `write_any.md` listed
  `agentsfleet/src/` and `agentsfleet/test/`, which stopped existing — a
  trigger path resolving to nothing is the silent green the card exists to
  prevent. The same stale prefix sat in the cross-runtime parity scan,
  where it made the JavaScript half read zero files.
- New `dispatch/write_pr_description.md`, routed from `AGENTS.orly.md` and
  `docs/EXECUTE_DOC_READS.md`: numbered append-only session units, measured
  diagrams, review dispositions, commands quoted with real output. The
  CHORE(close) checklist now names it instead of spelling the rules inline.
- `dispatch/write_rust.md` gains the constant-discipline section the new
  leaf enforces.

The one line the new lane newly reads, fixed in the same commit rather than
left for the next commit to trip over: `afd_core/tests/limits.rs` clamped a
bare `1_000` sitting beside `u32::MAX` in the same boundary array. The two
test different classes — far-above-the-ceiling versus the saturating edge —
so the literal became `FAR_ABOVE_CEILING` and now says which.

    bash audits/ufs.sh   →  OK: no violations across 2218 file(s)
    make lint-rustd      →  ✓ [rustd] Lint passed
    make harness-verify  →  ALL GATES GREEN

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>