0.5.1 — issue sweep: env strap double-run, valet parked-path symlinks

Fixes from v0.5.0 dogfooding. Suite: 165/165 bats green.

Fixed

• #18 — declaring the project env strap in straps: ran it twice per lifecycle (and fataled dry-run on fresh projects). The core-managed env strap is now filtered from the declared-strap resolution with a warning; run_env_strap remains its single runner.
• #19 — the valet strap's short-name symlink landed in dirname(worktree), which valet never scans when repos are reached through a symlink in a parked dir. valet-site now discovers the parked path that serves the main repo from the valet config's paths[] and places/removes the symlink there (falling back to the worktree parent; unsecure cleans both locations).

Verified / closed

• #17 — destroy already removes the per-branch state file and registry row; a regression test pins it. Residue on the reporter's synced tree came from their sync setup (deletions resurrected) — closed as an environment quirk.
• #13 — long valet names taking nginx down was fixed in 0.4.0 by valet-site's deterministic short-name truncation; closing as completed.