dracon-sync v0.113.5 — 2026-07-27

MEDIUM-finding remediation batch from AUDIT_FULL_2026-07-26.md.
Closes 4 still-open SYNC MEDIUMs (M1-M4):
- M1: detached_discard keyed per-(repo, task-generation)
- M2: filter-only early return preserves injected gitlinks
- M3: FilterOnly handle_ahead_push no longer flips benign repo
  (observed live browser-extensions-shared 73-min stall 2026-07-27)
- M4: main apply phase vs trailing-drain symmetry via shared
  apply_outcome closure

Also closes 14 unrelated pre-existing baseline clippy warnings.

851 tests pass (was 837 before this batch; 4 new regression tests).
cargo clippy ... -- -D warnings clean.
cargo build --release --locked clean.

See release-notes-v0.113.5.md for full notes.