docs: scrub GitHub-specifics after Gitea migration; add tea issue conventions

- Cargo.toml: repository -> git.lazyeval.net/oli/rdbms-playground
- requirements.md: backlog now tracked as Gitea issues
- ADR-0001 Amendment 1: distribution channel reopened post-migration
  (Decision text preserved per supersede-don't-rewrite)
- CLAUDE.md: issue-tracking working method + Gitea/tea operational section

CLAUDE.md

@@ -166,6 +166,17 @@ Key invariants in the code:
   until it settles. The ADR-0000 index-upkeep rule applies:
   every ADR change updates `docs/adr/README.md` in the same
   edit.
+- **Issue tracking.** Bugs and enhancements are filed as Gitea
+  issues (see *Issue tracking — Gitea via `tea`* below).
+  `docs/requirements.md` and the ADRs remain the source of truth
+  for **scope and decisions**; issues are the lightweight tracker
+  for **discrete work items**, cross-referenced from commits and
+  handoffs (e.g. `fix: … (#12)`). The project is near completion
+  of its initial requirements, so no heavyweight planning workflow
+  is run — the document-based requirements are augmented with
+  issue references as work proceeds. A change that touches a
+  *decided* area still earns an ADR; the issue references the ADR,
+  it does not replace it.
 - **Testing.** Per the user's global standards, tests are
   established before changes, bugs are reproduced with failing
   tests before being fixed, and "all green, no skips" is the
@@ -190,6 +201,64 @@ Key invariants in the code:
   `git commit` is preceded by an explicit message proposal
   and user approval. No AI attribution in commit messages.
 
+## Issue tracking — Gitea via `tea`
+
+Extends (does not replace) the generic Gitea/`tea` safety rules in
+the global `CLAUDE.md`. Use `tea` to manage Gitea issues; `tea
+--help`, `tea issues --help`, etc. for command reference.
+
+**Repo coordinates.** This repo lives on the self-hosted Gitea at
+`git.lazyeval.net` as `oli/rdbms-playground`. `tea` **auto-detects
+it correctly off the git remote** — verified — so plain `tea issues`
+works here even though the machine's *default* `tea` login is a
+different host (`git.oliversturm.com`). Pass `--login
+git.lazyeval.net --repo oli/rdbms-playground` only as a fallback if
+auto-detection ever slips. **Never** fall back to raw API calls
+(`curl`/`fetch`) when `tea` misbehaves — tokens leak into shell
+history; fix `tea` instead (usually `--login`/`--repo`).
+
+**Labels.** Preconfigured (`bug`, `enhancement` are in use).
+**Ask the user before creating new labels.** Create with `tea
+labels create --name <n> --color <hex> --description <d>`.
+
+### Critical gotchas
+
+- **`tea` blocks on stdin in a non-TTY → hangs.** `tea comment`,
+  `tea issue … --comments`, and similar **wait on stdin** when not
+  attached to a terminal, so they hang silently. **Always append
+  `< /dev/null`**, and wrap in `timeout 30` as a safety net:
+  `timeout 30 tea comment <idx> "$body" < /dev/null`. Verify the
+  write landed afterwards (re-fetch); don't trust a clean exit alone.
+- **Multi-line comment / description bodies**: heredocs do **not**
+  work with `--description` / the comment-body arg. Write the
+  markdown to a temp file and pass it via shell substitution: `tea
+  comment <idx> "$(cat /tmp/body.md)" < /dev/null` (same for `tea
+  issues edit --description "$(cat …)"`).
+- **Read an issue's RAW body** (for editing): the default/`--output
+  yaml` view is a lossy rendered box. Use JSON: `tea issue <idx>
+  --fields body --output json < /dev/null | jq -r '.body'`. **`tea
+  issues edit --description` replaces the WHOLE body** — splice
+  surgically and keep the raw backup before applying.
+- **Reopen**: use `tea issues reopen <index>`, NOT `tea issues edit
+  --state open`.
+- **Milestones** (not currently used here, but if introduced): set
+  with `tea issues edit --milestone "<name>" <idx>` (empty string
+  clears it). **Options MUST precede the `<idx>`** — flag-after-index
+  silently no-ops. The `tea issues create --milestone …` flag is
+  **unreliable** — set the milestone with a follow-up `edit` and
+  verify.
+- **Display blind-spot — don't loop on this.** `tea issue <n>
+  --fields milestone` and `--fields comments` render `None`/`0`
+  **even when set** — they are NOT a source of truth. Confirm a
+  **milestone** via the filtered list (`tea issues list --milestones
+  "<name>" --limit 100 | grep <idx>`; presence = set); confirm a
+  **posted comment** via `tea issue <n> --comments` (NOT the
+  `comments` count field). Labels/state/title DO render correctly on
+  the single-issue fetch; only milestone + comments don't.
+- **Pagination**: default ~50 issues. Use `--limit 100` (or more)
+  for full lists; `--state all` to include closed; `--output
+  tsv`/`json` for parseable output.
+
 ## Build hygiene
 
 `target/` is git-ignored and 100% regenerable, but it grows