Bump the catgraph pin from v0.11.0 to v0.13.0

[tsondru]

All four catgraph edges are pinned at v0.11.0 (Cargo.toml lines 51, 59, 67, 98).
catgraph v0.12.0 is tagged (2026-08-15) and is additive + bug-fix only — no
breaking surface, so this is a pin change plus cargo update -p and a gate run.

What the bump brings that matters here:

• Presentation::rewrite_depth() (catgraph #250) — the accessor that closes
  the serde-rebuild hazard this repo found at step 2. A presentation stored as
  its (equations, depth, engine) parts and rebuilt later could read the engine
  back but not the depth, so the rebuild silently restored the default 32 —
  no error, just a different bound and with it a different converged verdict on
  any presentation needing the longer budget. Rebuild through
  with_depth(depth) then set_engine(engine): no constructor takes both,
  and with_depth defaults the engine, so stopping there reintroduces the same
  silent default one slot over.
• CospanCanon::classes() (catgraph #254) — read access to the apex
  signatures. See the separate issue on what this does and does not enable for
  src/cospan.rs.
• Two silent wrong answers fixed (catgraph #252): PropExpr::from_permutation
  returned the identity for every permutation, and permute_side spliced
  Braid(0, n) — also the identity — on both sides. Both reached generic
  SymmetricMonoidalMorphism callers. This store does not appear to call either
  through the trait, but the bump is how it stops being reachable.

Worth taking on its own, independent of the cospan.rs question.

Re-run the five §3.8 gates after the bump.

[tsondru]

Retargeted v0.12.0 → v0.13.0 (2026-08-15). catgraph cut v0.13.0 the same day; it is a strict additive superset of v0.12.0, so there is no reason to stop at the interim tag. Title updated.

This is now the highest-value item on the board, because it is what unlocks #4 (replay) as well as Presentation::rewrite_depth().

What v0.13.0 adds on top of v0.12.0 — catgraph #249 and #255:

• RewriteStep, RewriteOutcome<G> and ContentKey<G> derive Serialize/Deserialize behind catgraph-applied's existing off-by-default serde feature. This repo already enables that feature (Cargo.toml:67-69), so no feature change is needed — the derives simply appear.
• Purely additive; no breaking surface anywhere in v0.11.0 → v0.13.0.

⚠ Coordinate the tag choice with tsondru/irreducible

Not a blocker for bumping, but it decides which tag, so it is worth knowing before picking one.

That repo's persist feature (its issue #15) pulls this store in as a dependency. When it returns, both repos sit in one lock against the same git URL — https://github.com/sustia-llc/catgraph — which must therefore resolve at exactly one tag. Two tags = split source identity = the Cospan<u32> / Span<u32> boundary-type mismatch its Cargo.toml documents at lines 77-83.

Current state: irreducible pins v0.2.0, this repo pins v0.11.0. v0.13.0 is the natural meeting point for both. Landing here first is fine — irreducible does not depend on this store while persist is out — but pinning an interim tag would just have to be redone.