chore(agent): track .agent/ planning tree in git

Remove the blanket .agent/ gitignore so the phase roadmap, user
stories, reports, and PLAN.md are versioned with the code. Only
runtime artifacts (.agent/phase-sessions/, .agent/pipeline.log)
remain ignored. Update AGENTS.md git protocol rule to match.

.agent/phases/todo/62_ui_customization/04_docs.md

@@ -0,0 +1,31 @@
+# Task 04 — Document the customization surface (.env.example + README)
+
+**Phase:** `62_ui_customization` · **Source:** `TODO.md:3` — "Allow UI customization. This is brain of reese, but I want anyone to be able to deploy it with their name…"
+**Story:** n/a (TODO-derived)
+
+## Objective
+A deployer who has never seen the codebase can find, understand, and apply all four customization vars (name, placeholder, footer, theme) from the docs alone — the house standard set by the phase-39 `BOR_APP_NAME` documentation.
+
+## Work
+1. `.env.example` — in the `# --- App ---` block, right after the `BOR_APP_NAME` comment line (~L9), add (same comment style, phase-cited):
+   ```bash
+   # BOR_INPUT_PLACEHOLDER=Ask me anything…   # composer placeholder, chat page (phase 62)
+   # BOR_FOOTER_TEXT=Powered by self-hosted models   # footer line on every page (phase 62)
+   # BOR_THEME=            # filename under frontend/assets/themes/ (e.g. indigo.css) — overrides the built-in palette; empty = built-in (phase 62)
+   ```
+2. `README.md` — two edits:
+   - The env-var table (the `BOR_APP_NAME` row sits ~L734): add three rows immediately after it, matching that row's column style — what it affects, the default, the no-op-when-unset contract:
+     - `BOR_INPUT_PLACEHOLDER` | `Ask me anything…` | the chat composer placeholder; applied by `assets/brand.js` from `GET /api/config`; unset ⇒ the template default
+     - `BOR_FOOTER_TEXT` | `Powered by self-hosted models` | the footer line on all 9 pages (the `.footer-text` spans); same mechanism
+     - `BOR_THEME` | *(empty)* | a filename under `frontend/assets/themes/` (e.g. `indigo.css`) — a `:root` palette override injected after `styles.css`; the server refuses a malformed name at startup (bare `^[a-z0-9_-]+\.css$` filename); a missing file degrades to the built-in theme; unset ⇒ built-in dark-tech palette
+   - A short **"Customizing the look"** subsection (3–6 sentences) placed directly above or below the env table (mirror the placement of the nearest feature section — the executor picks the spot that reads best and notes it in the task report): the app ships as "Brain of Reese" but every identity string is an env var (`BOR_APP_NAME` / `BOR_INPUT_PLACEHOLDER` / `BOR_FOOTER_TEXT`), themes are plain CSS variable overrides (`frontend/assets/themes/README.md` is the authoring guide, `indigo.css` the example), and everything unset renders the defaults byte-identically.
+3. No code changes in this task.
+
+## Testing & Quality
+- Docs-only; `uv run pytest` green unchanged; `uv run ruff check . && uv run pyright` clean.
+- Coverage: **>90%** on `app/` (validate.sh gate).
+
+## Completion Criteria
+- [ ] `.env.example` carries the three new commented vars in the App block with the exact default values (so copy-paste of the example reproduces the defaults).
+- [ ] README env table has the three rows + the "Customizing the look" subsection; the README builds/reads cleanly (no broken table rows, links resolve — `frontend/assets/themes/README.md` exists from task 03).
+- [ ] Full suite green, lint + types clean.