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

The five UI items in TODO.md become an executable pipeline. Planning files
only — no application code changed.

- 01_severity_language: one Python threshold table + `severity` on the
  values the pages colour, plus the .hero style. Today the thresholds are
  magic numbers at six JS call sites (75/90 here, 80/92 there), which is
  exactly how "same colour, four meanings" happens.
- 02_overview_fleet_and_alerts: /api/summary gains a derived `alerts`
  list; the page drops to fleet + warnings. Unconfigured sources must not
  alert — that is invariant 3, tested.
- 03_system_per_host_panels: per-host hero cards, no per-core, shared
  multi-host charts and the detail picker deleted. The six card metrics
  already exist in the payload, so the first task pins them with tests
  instead of inventing fields.
- 04_llm_chart_readability: charts.js already exports sparkline() and no
  page calls it — that is why the page reads flat. Port llm_monitor's
  drawSpark behaviour (fixed max, right growth, p95 foots) and keep the
  provenance tags.
- 05_ups_hero_battery_glyph: charge/load/runtime hero + an SVG battery
  whose fill is the charge, verified against both real UPSes and the
  low-charge/on-battery states only the simulator can produce.

PLAN.md records the ratified anchors and the deviation worth knowing:
severity vocabulary is ok|warn|fail, matching dash.css and nut.py, not the
"danger" wording in the proposal — one synonym for one colour.

TODO.md cleared to a bare heading; the items are now phases. .gitignore
stops ignoring all of .agents/ (the roadmap is project history) while
keeping phase-sessions/ and pipeline.log out. deploy/nut-sudoers rewritten:
its header still blamed a port mystery that is solved; the remaining need
is reading upsd.users so adding a scoped dashboards user does not delete
the accounts upsmon authenticates as.

LLM-Generated: true

.agents/phases/todo/04_llm_chart_readability/00_phase.md

@@ -0,0 +1,51 @@
+# Phase 04 — LLM page is readable again
+
+**Source:** `TODO.md` L6 — "LLM usage drifed from initial request to copy Experimental/llm_monitor. The charts got less useful. Need simplified and more readable."
+**Story:** n/a
+**Context:** `.agents/PLAN.md` → *Anchors* (hand-rolled SVG only), `~/Projects/Experimental/llm_monitor/static/index.html` (the reference implementation), `src/dashboards/web/static/page-llm.js` (`CELLS`, `makeCharts`), `src/dashboards/web/static/charts.js` (`sparkline`, `LineChart`), `src/dashboards/sources/llm.py`
+
+## Objective
+
+The LLM page drifted into a 14-cell grid where everything is the same size and nothing shows
+recent shape. Bring back what made `llm_monitor` legible — big throughput numbers, a sparkline
+in each metric cell, percentiles as foot lines — without losing what this project added since:
+per-engine provenance tags, history windows, and severity colour.
+
+`llm_monitor` is the design reference, not a dependency. It is a separate app on `:8095` and
+stays that way; nothing here imports from it.
+
+## Dependencies
+
+- `01_severity_language` (todo) — KV-cache pressure and queue depth get coloured from the
+  API verdict, not a per-page threshold.
+- `03_system_per_host_panels` (todo) — touches `charts.js` first; this phase builds on the
+  same shared helpers and must not fight it for them.
+
+## Tasks
+
+1. `01_chart_set_decision.md` — read both implementations side by side and write the decision note (which cells live, which get sparklines, what is demoted).
+2. `02_sparkline_upgrade.md` — bring `DashCharts.sparkline()` up to `llm_monitor`'s `drawSpark` behaviour: right-aligned growth, fixed max, current/max labels, severity colour.
+3. `03_llm_layout_simplified.md` — restructure `llm.html` + `page-llm.js`: hero throughput, compact sparkline cells, percentile foot lines, conditional alarm cells.
+4. `04_side_by_side_verification.md` — verify against `llm_monitor` on `:8095` with the same live engines.
+
+## Testing & Quality
+
+- Python: none expected beyond the phase-01 severity fields; `/api/llm/*` stays as-is
+  (additive-only anchor).
+- `uv run pytest -m live --live` must stay green — `test_engine_still_publishes_the_series_we_parse`
+  is the assertion that the numbers on screen are backed by resolved upstream series.
+- Browser: both engines live (gufo on `deskwork:8731`, vLLM on `driveripper:8000`), plus the
+  single-engine case: with one `*_BASE_URL` unset the page must show one clean half rather
+  than a red panel.
+- Coverage: ≥94% overall maintained.
+
+## Completion Criteria
+
+- [ ] decode and prompt throughput are the two largest numbers per engine, colour-coded
+- [ ] every remaining metric cell carries a sparkline showing the selected window
+- [ ] latency cells show mean **and** p95 without needing a hover
+- [ ] a source-provenance tag is still visible on every throughput number (`AGENTS.md`: never invent a number)
+- [ ] `/llm` with only one engine configured still renders cleanly
+- [ ] screenshots of this page and `llm_monitor` side by side in `data/logs/`, plus `NOTES-chart-set.md`
+- [ ] `uv run pytest` green, coverage ≥94%, `ruff` + `pyright` clean
+- [ ] no behavior change in completed phases