dashboard.css + docs: migrate MESS4GE FL0W body layout + final cookie scrub (#712 batch 13)

Second dashboard.css batch — scrubs all remaining #NNN cookies
(post-batch-12 dashboard.css went from 51 → 36 raw matches, mostly
hex colors). This batch zeroes out the actual issue refs.

Moved to docs/web-ui.md::FL0W page:
- **MESS4GE FL0W (extended)**: msgrow flex-wrap row + body
  flex-basis: 100% + min-width: 0 rationale (~10 lines new prose).
  Without flex-basis: 100% the body sat inline eating whatever the
  chips left, starting ~30ch in on long timestamps + agent names
  and wrapping awkwardly. Pushing it to its own line lets the body
  use the full row width.

Collapsed in dashboard.css (en passant cookie scrubs across many
small comments):
- #485 msgrow body flex (→ FL0W docs pointer)
- #450 inbox max-height (→ inline rationale only, cookie dropped)
- #451 side-panel drag-to-resize × 2 (→ Side panel docs pointer)
- #369 dashboard chrome (→ Tab strip pointer)
- #416 full-width layout (→ inline rationale, cookie dropped)
- #389 slug banner footer (→ inline rationale, cookie dropped)
- #369#issuecomment-3437 + #362 + #383 + #383 + #362 flow.html
  section (→ FL0W page pointer + per-agent header pills pointer)
- #375 tail pill stacking context (→ Per-agent page Terminal-wrap
  pointer to existing docs)
- #66 ctx badge thresholds (→ Container row Line 1 pointer)
- #541 panel-body column flex × 2 (→ inline rationale, cookie dropped)
- #188 / #192 image preview (→ Side panel pointer)
- #275 bulk select × 2 (→ inline, cookies dropped)
- #259 background meta-update (→ inline, cookie dropped)
- #474 inline edit button + form (→ inline, cookies dropped)
- #466 interval composer (→ inline, cookie dropped)
- #535 schedules-as-table × 2 (→ SCH3DUL3S tab pointer + inline)
- #564 inline create row (→ inline, cookie dropped)
- #443 selection bar (→ Selection bar pointer)
- #486 M0V3 → <pick> (→ Selection bar pointer)
- #459 scheduled prompts tab section (→ SCH3DUL3S tab pointer)

dashboard.css: ~20 issue refs scrubbed in this batch + ~10 lines
substantive prose migrated to MESS4GE FL0W. Total dashboard.css
across batches 12 + 13: 51 raw matches → 0 issue-ref cookies
(only hex colors remain).

docs/web-ui.md

@@ -383,7 +383,14 @@ newest-first.
 **MESS4GE FL0W** — live broker tail wrapped in a `.terminal-wrap`.
 Cold load backfills the last ~200 messages from `/dashboard/history`;
 live frames arrive on `/dashboard/stream`. Each row is one broker
-event — `sent` or `delivered` — with `from → to: body`. Sticky-
+event — `sent` or `delivered` — with `from → to: body`. The row is
+a `flex-wrap: wrap` container holding ts / arrow / from / sep / to
+chips inline; the **body wraps to its own full-width line below**
+the chips (`flex: 1 1 100%`) so the body always gets the full row
+width down to the content edge — long timestamps + agent names
+used to push the body ~30ch in and force awkward narrow-column
+wraps. `min-width: 0` keeps `word-break: break-word` effective so
+the body doesn't force the row wider than its container. Sticky-
 bottom auto-scroll + "↓ N new" pill. Below the stream sits a
 terminal-style compose box: `@name` picks the recipient (sticky via
 localStorage; auto-complete from the live container list, Tab/Enter