feat: local issue cache and draft-then-push workflow

Replace fetch_issue.py with four scripts around a flat, greppable cache in
tmp/issues/. Planning stays offline and issues reach Gitea in one push:

- issue_get.py: fetch by key or by filter (--milestone/--label/-q). The list
  endpoint carries issue bodies, so a whole milestone costs one request per 50
  issues. Gitea silently ignores an unresolvable milestones= filter and returns
  the entire backlog, so the milestone is resolved up front and every returned
  issue is re-checked locally. --deps walks the dependency graph downwards via
  the structured sections plus native dependencies and writes tree-<slug>.md.
- issue_push.py: validate a local draft against the canonical format, create
  missing labels with the right colors and exclusivity, POST, delete the draft.
- issue_list.py: discovery to stdout, writes nothing.
- issue_index.py: rebuild INDEX.md from what is on disk.

Files use one metadata field per line with inline lists so plain grep works
without a parser. This is a cache and a drafting area, not a mirror: no drift
tracking, no sync back.

Projects are not fetchable — the projects API is 404 on Gitea 1.26; documented
alongside the milestone caveat.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

skills/use/scripts/issue_list.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+"""
+issue_list.py — discovery: which issue numbers exist, one line each.
+
+Prints to stdout and writes nothing: INDEX.md is a map of the local cache, and
+this command deliberately does not pollute it. Use it to pick numbers, then
+fetch them with issue_get.py.
+
+    #42  open    type/task, tech/sql            Wire sqlc into the repo layer
+
+Usage:
+    issue_list.py [--state open|closed|all] [--label L]… [-q TEXT]
+                  [--milestone M] [--limit N] [--page N] [--repo owner/repo]
+
+Login: the operator's pin from .claude/settings.local.json (see /tea:auth).
+"""
+import argparse
+import os
+import sys
+
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+from _tea import list_issues, repo_base, require_login  # noqa: E402
+
+
+def main():
+    ap = argparse.ArgumentParser(description="List Gitea issues (stdout only, no files)")
+    ap.add_argument("--state", default="open", choices=["open", "closed", "all"])
+    ap.add_argument("--label", action="append", default=[],
+                    help="filter by label; repeat for AND")
+    ap.add_argument("-q", "--query", help="search text in title/body")
+    ap.add_argument("--milestone", help="milestone id or title")
+    ap.add_argument("--limit", type=int, default=30)
+    ap.add_argument("--repo", help="owner/repo (default: auto-detect from CWD git remote)")
+    args = ap.parse_args()
+
+    login = require_login()
+    got, ms_title = list_issues(login, repo_base(args.repo), state=args.state,
+                                labels=args.label, query=args.query,
+                                milestone=args.milestone, limit=args.limit)
+    for iss in got:
+        labels = ", ".join(l.get("name", "") for l in iss.get("labels") or []) or "-"
+        print("#%-5d %-7s %-38s %s" % (iss["number"], iss.get("state", ""),
+                                       labels[:38], iss.get("title", "")))
+    scope = " in milestone %s" % ms_title if ms_title else ""
+    print("%d issue(s)%s — fetch them with: issue_get.py %s"
+          % (len(got), scope,
+             ("--milestone %s" % args.milestone) if args.milestone else "<n>"))
+
+
+if __name__ == "__main__":
+    main()