chore(agent): phase roadmap from TODO.md, 5 phases

Convert the 11 TODO items to phases 20-24 (masthead/nav polish,
page cleanups, /disks hiding unconfigured hosts, LLM rate window,
dev mTLS rollout). TODO.md cleared; items now live in
.agents/phases/todo/.

LLM-Generated: true

.agents/phases/todo/21_page_cleanups/00_phase.md

@@ -0,0 +1,34 @@
+# Phase 21 — Page cleanups: pause, GPU values, certs scroll
+
+**Source:** `TODO.md` L7, L9, L12 — "remove the pause button, GPU data as its own values, /certs table horizontal scroll"
+**Story:** n/a
+**Context:** `src/dashboards/web/pages/{disks,llm,system,ups}.html` line 25 (the `#pause` button, the only one in the served markup — `/`, `/certs` and `/settings` have none), `src/dashboards/web/static/app.js` (lines 587–615 the `poll()` `_paused` plumbing, lines 773–783 the `#pause` binding plus the `Space` shortcut), `src/dashboards/web/static/dash.css` line 203 (the comment naming the pause button), `src/dashboards/web/static/page-system.js` (lines 150–156 `gpuSub()` — the dense sub-line the TODO quotes, lines 164–188 `renderGpuSlot()`, line 72 the `data-k="gpus"` hero slot), `tests/test_api.py` (line 1425 — the six-heroes pin: "exactly six heroes: CPU, MEM, TEMP, DISK, GPU, NET", asserted over the three captures: discrete GPU, APU, no-GPU), `src/dashboards/web/pages/certs.html` line 81 (`<table class="data" id="agents-table">` — no `.scroll` modifier; `dash.css` gives `table.data` a scroll container only with the `.scroll` class), `src/dashboards/web/static/page-certs.js` (lines 55–56 — the table element references)
+
+## Objective
+
+Three small page-level cleanups, one per workstream: the pause button is gone from every page (the hidden-tab skip stays — a background tab idling its polls is not the operator's pause), the `/system` GPU data is split out of the dense sub-line into its own labelled values and a host with no GPU **omits** the slot instead of printing `n/a`, and the `/certs` agents table scrolls horizontally so the right-hand columns are reachable on a phone. No API surface changes; the pins that name the old behaviour (six heroes incl. an `n/a` GPU slot, the unpinned pause button) are rewritten, not left rotting.
+
+## Dependencies
+- `20_masthead_nav_polish` (todo) — the pause button lives in the masthead row task 01.01 reflows, and the `/system` hero row is re-measured under the new bar; landing 20 first keeps 21's diff confined to the page bodies.
+
+## Tasks
+1. `01_remove_pause_button.md` — delete the button, the `Space` shortcut, the `setPaused`/`_paused` plumbing and the CSS comment; the hidden-tab skip survives
+2. `02_gpu_own_values.md` — the dense `gpuSub()` line becomes four labelled values per card; a GPU-less host omits the slot (five heroes, no `n/a`)
+3. `03_certs_table_scroll.md` — `#agents-table` gets the `.scroll` modifier so its right-hand columns are reachable at phone width
+
+## Testing & Quality
+- Unit/integration: `tests/test_api.py` — the served-page pins: the pause button absent from the four pages (a return of `#pause` fails a test), the six-heroes pin rewritten (GPU-present host: six, GPU-absent host: five with no `data-k="gpus"` slot), the `#agents-table` `.scroll` pin; `tests/test_system_contract.py` + `tests/card_contract.py` stay green (the API fields are unchanged — only the page's reading of them moves)
+- Coverage: **>90%** on new/modified code (the phase is markup + JS + CSS; the gate applies to the changed Python test files)
+- The phase is "Complete" only when the **entire** project test suite passes 100% (every test in the project, not just this phase's)
+
+## Documentation & Consistency
+
+- The final pass reviews `README.md` and `AGENTS.md` in full against the project as it stands after this phase — fixing every inconsistency found, **including pre-existing ones not caused by this phase**. AGENTS.md's `/system` paragraph ("a missing number or verdict — gateway's CPU temp, any host's absent GPU — prints `n/a` **uncoloured**") is the one rule this phase inverts for the GPU slot (the CPU-temp `n/a` stays — the TODO quotes the GPU line only); the sentence is split, the GPU half rewritten to the omission rule, and the pause button's mention in the masthead comment dropped.
+
+## Completion Criteria
+- [ ] no page serves a `#pause` button or binds the `Space` key; a hidden tab still skips its polls (served-bytes pin + a CDP `visibilitychange` check)
+- [ ] `/system`'s GPU slot prints model / VRAM / pool / temp as four labelled values; a GPU-less host (the no-GPU capture, gateway) renders five heroes with no GPU slot and no `n/a` in it (screenshots in `data/logs/`)
+- [ ] at 360 px the `/certs` agents table scrolls horizontally to its last column (screenshot in `data/logs/`)
+- [ ] `uv run pytest` green, coverage not down, `ruff` + `pyright` clean
+- [ ] `bash .agents/validate.sh` green (including `node --check` of the modified page scripts)
+- [ ] no behavior change in completed work: the six-hero order on GPU hosts, the hidden-tab skip, the GPU history charts, the `/certs` row contents and the event pager are all unchanged