feat: work the sync backlog — comments, labels, refs, closed issues

Five tracker issues, all in the bridge layer except the last.

pull.py fetches comments by default (#6). The thread was reachable only
through --comments, and only for a single issue, so a bulk pull left every
local copy silently incomplete: a missing <id>.comments.md could mean "no
comments" or "never asked". Now every written issue gets its thread, in key
and filter mode alike; an empty one costs no request (the count rides in the
list payload) and writes no file, and a file left over from an earlier pull
is deleted. --cached skips the thread along with the body. The --comments
flag is gone.

labels.py bootstraps the canonical label set (#7). Labels used to appear as a
side effect of the first push that happened to use them, so a repo could not
be filtered by type/bug until somebody pushed a bug. The set is finite and
already described by the domain taxonomy — 6 type/* and 5 severity/* — which
makes it a run, not a decision. Names and exclusivity come from issue.TYPES /
SEVERITIES / EXCLUSIVE_NS, colors from map.label_specs; no list is duplicated.
An exact name is never re-created or patched. Lookalikes (bug, Bug, "type:
bug", kind/bug) are reported with their id and left alone — renaming somebody
else's label is a decision, not a migration. Color or exclusive drift is
printed, and changed only under --fix.

branch: carries Gitea's ref (#8). map.to_payload sends ref only when the field
is non-empty, since ref="" would clear whatever the server has; from_api reads
it back; push fills an empty one from `git rev-parse --abbrev-ref HEAD` and
writes it into the issue file. A hand-written value is never overwritten, on
create or on --update. Detached HEAD and running outside a repo warn and send
no ref. Reading the branch is the only thing these scripts ask of git. The
domain needs no change: unknown keys already ride in Issue.extra and render
after the domain fields.

Bulk pulls no longer store closed issues (#10). Filter mode wrote every
payload the server returned, so --state all dragged the closed backlog into a
store that gets read whole — INDEX.md, grep over tmp/issues/*.md. They are
still enumerated, the number left out goes to stderr, and an issue already on
disk is refreshed either way so the local copy learns it was closed instead of
staying open forever. --state closed stores them, and key mode is exempt: an
address is not a bulk read.

/tea:issue gains a "Writing a proper description" procedure (#9). Six steps
from reading an issue to issue_check.py, the rule that a missing fact is found
in the repository or asked about rather than invented, and the note that the
procedure is identical for origin: local and origin: gitea while delivery to
the tracker belongs to /tea:sync. No new script.

Verified: labels.py run for real against claude-skills/tea (9 created, 2
already present) and idempotent on a second run; pull.py exercised live for
the closed-skip, --state closed, key-mode and comment paths; the push write
path covered offline with the transport stubbed. skills/issue/scripts/ still
imports stdlib only, with no subprocess.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

skills/sync/SKILL.md

@@ -38,9 +38,10 @@ the `tea-guard` hook reads. No pin → exit with a pointer to `/tea:auth`.
 | Script | What it does |
 |---|---|
 | `remote.py [--state] [--label] [--milestone] [-q TEXT]` | discovery: one line per Gitea issue to stdout, writes nothing |
-| `pull.py <key…>` or `pull.py --milestone M \| --label L \| -q TEXT` | Gitea → `tmp/issues/<id>.md` |
+| `pull.py <key…>` or `pull.py --milestone M \| --label L \| -q TEXT` | Gitea → `tmp/issues/<id>.md`, plus `<id>.comments.md` when the thread is not empty |
 | `push.py [id…] [--update] [--dry-run]` | local → Gitea; validates first, stamps `gitea:` on success |
 | `comment.py <id> --file F \| --body TEXT [--edit N]` | post or edit a comment, then refetch the thread |
+| `labels.py [--dry-run] [--fix]` | bootstrap the canonical `type/*` + `severity/*` set in a repo; exact names left alone, lookalikes reported, drift fixed only with `--fix` |
 | `map.py`, `_gitea.py` | the two layers the commands import — not commands |
 
 Key forms for `<key>`: `42`, `#42`, `owner/repo#42`, or a full issue URL. Repo
@@ -84,6 +85,21 @@ not one per issue. Filters AND together; `--state` defaults to `open`;
 **A pull overwrites the local body.** It is a fetch, not a merge — unpushed
 local edits are lost. `--cached` skips issues already on disk.
 
+**Closed issues stay out of the store.** In filter mode they are enumerated
+but not written: `--state all` still shows the whole picture, only `--state
+closed` puts one on disk, and the number left out goes to stderr. An issue
+already on disk is refreshed either way — the local copy learns it was closed
+instead of staying open forever. Key mode is exempt: `pull.py 1` fetches a
+closed issue as always, because an address is not a bulk read.
+
+**Comments come with every pull** — there is no flag. An issue that has a
+thread gets `tmp/issues/<id>.comments.md` beside it, in key mode and in filter
+mode alike, and the issue's output line says how many. An issue with none
+costs nothing: the count arrives in the list payload, so no request is made
+and no file is written — and a file left over from a thread that has since
+been emptied is deleted. `--cached` skips the thread along with the body, so a
+skipped issue makes no request at all.
+
 Two traps this handles for you:
 
 - **Gitea silently ignores an unresolvable milestone filter** and returns the
@@ -125,8 +141,33 @@ Missing labels are created with the canonical color and, for `type/*` and
 (tea 0.14.2), so it goes through `tea api`. Colors live in `map.py`; the names
 and their meaning come from the domain taxonomy.
 
+That is per-push and piecemeal: a repo only ever grows the labels its issues
+happened to use, so filtering by `type/bug` in the web UI stays impossible
+until someone pushes a bug. `labels.py` lays down the whole set — the 11
+`type/*` and `severity/*` names — in one run:
+
+```bash
+python3 <skill-base-dir>/scripts/labels.py --dry-run   # the plan, no writes
+python3 <skill-base-dir>/scripts/labels.py             # create what is missing
+```
+
+It reads the repo's labels first. An exactly-matching name is never re-created
+and never patched. A **lookalike** — `bug`, `Bug`, `type: bug`, `kind/bug` —
+is reported with its id and left alone: renaming somebody else's label is a
+decision, not a migration. A color or `exclusive` that drifted is printed, and
+changed only under `--fix`. Running it twice creates nothing. `tech/*` and
+`comp/*` are open-ended by design and stay push-created.
+
 A milestone must already exist in the repo — push attaches, it does not create.
 
+`branch:` is Gitea's `ref`, the branch the work actually lives on. Push fills
+an empty one with the current git branch (`git rev-parse --abbrev-ref HEAD`)
+and writes it back into the issue file; a value already there is never
+overwritten, neither on create nor on `--update`. On a detached HEAD or outside
+a git repo no `ref` is sent and a warning names the issues that went up without
+one. Reading the branch is the only thing these scripts ask git for — they
+never check out, create, or write anything.
+
 ## What crosses the boundary, and what does not
 
 | domain | Gitea | note |
@@ -138,6 +179,7 @@ A milestone must already exist in the repo — push attaches, it does not create
 | `assignees` | `assignees[]` | logins |
 | `milestone` | `milestone.title` | resolved to an id on write |
 | `depends` | — | slugs; seeded from `#N` on pull |
+| — | `ref` | lands in `branch:`; sent only when non-empty |
 | — | `number`, `html_url` | lands in `gitea:` / `url:` |
 
 `depends:` is always slugs. The body's `## Depends on` section is human prose
@@ -146,8 +188,7 @@ from the `#N` it finds there, a push never rewrites what the author wrote. A
 translator that edits prose churns the body on every round trip.
 
 Comments are **pull-only** in the store: `<id>.comments.md` is written by
-`pull.py --comments` and `comment.py`, and editing it by hand changes nothing
-in Gitea.
+`pull.py` and `comment.py`, and editing it by hand changes nothing in Gitea.
 
 ## Drift