v0.16.0 - Generic delete tool

Added

• Generic delete(id, type) MCP tool in general/tools/: the
  type-dispatched hard-delete for the eleven whole-body domains (type is
  one of req/uc/tsk/qa/prb/gol/rsk/dec/sop/feat/vcr;
  adr is not supported). Resolves the document by id under the
  domain's own per-id lock and removes it — the single *.md file for the
  ten flat domains, or the entire <base>/<id>/ folder for feat —
  returning the deleted path as a string. An invalid id (path-injection
  attempt or wrong format) is a ValueError raised before any file access;
  a missing document is the domain's own XNotFoundError; an I/O failure
  during the delete is a DeleteError (an OSError subclass). This is
  the sole delete entry point: every current and future domain implements
  a delete adapter in the generic tool, never a per-domain delete_<d>
  tool.
• A reusable, doc-type-agnostic path-safety module
  general/tools/_path_safety.py: assert_no_traversal, assert_uuid,
  assert_feat_id, validate_id, and assert_within — pure, no-I/O
  guards preventing path-injection through type/id inputs and confining
  resolved paths to their base directory. Wired into the new delete tool
  now; designed so the get_<d>, update, and set_status tools can
  adopt it later with zero rework (they are not modified in this change).

Changed

• The release SOP (now active — its status was draft until the first
  release executed under it succeeded end to end, v0.15.0) was clarified:
  tool prerequisites and the stage-to-step execution map up front in
  Scope, the fast-forward-only merge mechanism the script actually uses
  (pre- and post-merge SHA assertions around the plain merge method,
  replacing the description of a nonexistent gh pr merge --ff-only),
  the publication workflow's name ("Publish to PyPI") vs. file
  (.github/workflows/publish.yml) distinction, and a dedicated
  precaution about the old gh 2.4.0 the script targets.

Removed

• BREAKING (0.x): the eleven per-domain delete_<d> stub MCP tools are
  deleted outright (no deprecated wrappers): delete_req, delete_uc,
  delete_tsk, delete_qa, delete_prb, delete_gol, delete_rsk,
  delete_dec, delete_sop, delete_feat, delete_vcr — each was a
  registered stub that always raised NotImplementedError. The eleven
  per-domain delete_<d>.py modules, their __init__.py registrations,
  and their stub tests are gone with them. Callers must switch from
  tools/call --tool-name delete_<d> to tools/call --tool-name delete
  with the explicit type parameter (see "Added" above).

Fixed

• scripts/release.sh: the pr-merge, publish-wait, status, and
  release-notes stages no longer rely on gh CLI features that do not
  exist in this environment's gh 2.4.0 — a nonexistent --ff-only
  merge flag, gh run list --commit, gh run view --json jobs, and
  gh release view --json/gh release edit. Fast-forward-only merging
  is now enforced by pre-merge and post-merge SHA assertions around the
  plain merge method; the publication run is located by workflow name
  ("Publish to PyPI") plus the tag's commit SHA (filtered with jq);
  the GitHub Release is read and its notes set through gh api.