M8-02: Add WalkerLimits to production scanning

[DrunkOnJava]

Created from the roadmap audit in TODO.md.

Source: https://github.com/DrunkOnJava/rvt-rs/blob/main/TODO.md#L951
Tracking commit: 1ec8105

Scope

Labels: priority:P1, type:security, area:walker

• Ensure brute-force scans have configurable limits:
  • max scan bytes
  • max candidates
  • max trial offsets
  • max per-record decode bytes
• Apply limits in CLI, Python, and WASM.

Acceptance criteria:

• Crafted large files cannot trigger unbounded candidate scanning.
• Limit hits return diagnostics.

Definition of done

• The TODO acceptance criteria for this section are implemented or explicitly superseded by a linked decision.
• Tests, fixtures, or documentation are added at the level appropriate to the change risk.
• User-facing behavior and limitations remain honest in README/docs/viewer messaging.
• Relevant CI checks pass before the issue is closed.

[DrunkOnJava]

Implemented in b6f28a5 (feat: bound walker production scans).

Summary:

• Added explicit walker scan/decode limits for max scan bytes, retained candidates, trial offsets, per-record decode bytes, and container records.
• Routed limits through production IFC export, diagnostic export, rvt-ifc, rvt-doc, Python RevitFile(...), and WASM viewer entry points.
• Added diagnostics for bounded scan paths so limit hits surface as warning codes instead of silently running unbounded work.
• Added regression coverage for scan byte caps, candidate caps, trial-offset caps, per-record decode caps, default-limit compatibility, and truncated container payload rejection.
• Updated Python and viewer API docs for the new resource limit surfaces.

Verification:

• cargo test -> 739 lib tests plus integration/doc tests passed.
• cargo clippy --all-targets -- -D warnings passed.
• cargo clippy --features wasm --no-default-features -- -D warnings passed.
• cargo check --manifest-path rvt-py/Cargo.toml passed.
• git diff --check passed.
• Stub-pattern scan over touched files passed.
• GitHub Actions for b6f28a5: 21/21 check runs passed.