M8: GUI polish, n8n workflow-3 fixes, RAGcore retrieval root-cause and fix

GUI: dashboard Attention Queue presents a curated severity mix instead of pure
severity-sort (grouped Now/Today/Later headers); Today's Movements seed data
curated so a fresh reset shows a credible day (2+ departures, 2+ returns), with
a new seed-integrity test; About Demo restructured into a compact grid with
progressive disclosure for technical sections; Duplicate Merge shows match/conflict
counts, hides matching fields by default, and previews the final merged record
before confirmation.

Repo hygiene: removed a stray empty `backend;C` directory and an untracked 31MB
zip export; `.gitignore` now excludes future archive exports.

n8n: fixed invalid JSON (a missing `},` between two node objects) in the committed
`fleet-ops-vehicle-return.json` -- the file could not be parsed. Live-validated
workflow 3 (RAGcore Procedure Sync): found and fixed a real defect (three body
parameters had a stray trailing `}}`) and a missing Error Workflow wiring, both
via the safe `n8n import:workflow` CLI path; exported the corrected, still-
inactive workflow as the new source of truth and updated MANIFEST.md/check_drift.py.
Publishing it (starts real daily unattended runs) remains a separate decision.

RAGcore: root-caused and fixed (live, approved) the "zero retrieval candidates"
bug -- a filesystem permission bug (`embedding_profiles.json` unreadable by the
app's own runtime user) that broke every retrieval call before it reached Qdrant.
Every other suspect (grants, scope resolution, Qdrant filters, embeddings) was
verified healthy first. Found a second, deeper gap: the reranker adapter calls
an Ollama HTTP route that does not exist on the deployed Ollama version, so
`/v1/answers` still returns `not_answerable`. `KNOWLEDGE_PROVIDER` stays `demo`
until that is resolved on the RAGcore side. Evidence-based MCP Hub integration
status (real tool-call audit history, not just a boolean flag) replaces the old
`configured`/`not_configured` guess. Full findings in
`docs/final-integrations/current-state-audit.md`.

Backend: 172 tests passing, ruff clean, mypy clean (50 files). Frontend: tsc
clean, production build clean.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/styles.css

@@ -193,6 +193,8 @@ a:hover { color: var(--teal); }
 .row-link { position: absolute; inset: 0; z-index: 1; border-radius: inherit; }
 .row-link:focus-visible { outline: 2px solid var(--focus); outline-offset: -2px; }
 .attention-list li.row-clickable:hover .attention-title, .movement-timeline li.row-clickable:hover .movement-ref { color: var(--teal-dark); }
+.attention-tier + .attention-tier { border-top: 1px solid var(--line); }
+.attention-tier-label { margin: 0; padding: 9px 18px 5px; color: var(--muted); font-size: .62rem; font-weight: 700; text-transform: uppercase; letter-spacing: .08em; }
 .data-table tr.row-clickable:hover { background: var(--surface-subtle); }
 .data-table tr.row-clickable .cell-link { position: relative; z-index: 2; }
 
@@ -249,6 +251,12 @@ details summary { cursor: pointer; color: var(--teal-dark); }.data-table details
 .about-cta { display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; background: var(--teal-pale); border-color: #bfe6df; }
 .about-cta strong { display: block; color: var(--ink); font-size: .85rem; }
 .about-cta p { margin: 2px 0 0; }
+.about-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 12px; margin-bottom: 18px; }
+.about-grid .about-card { margin-bottom: 0; }
+.about-details summary { cursor: pointer; color: var(--ink); font-size: 1rem; letter-spacing: -.015em; font-weight: 700; }
+.about-details[open] summary { margin-bottom: 8px; }
+.about-details summary::-webkit-details-marker { display: none; }
+.about-details summary:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
 .detail-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 1px; margin: 0; background: var(--line); border: 1px solid var(--line); }
 .detail-grid div { min-height: 76px; padding: 13px 14px; background: white; }
 .detail-grid dt { margin: 0; color: var(--muted); font-size: .63rem; font-weight: 700; text-transform: uppercase; letter-spacing: .065em; }.detail-grid dd { margin: 7px 0 0; color: var(--ink); font-size: .82rem; font-weight: 700; }
@@ -288,6 +296,14 @@ details summary { cursor: pointer; color: var(--teal-dark); }.data-table details
 .duplicate-compare { margin-top: 18px; }.duplicate-compare fieldset { margin: 15px 0; padding: 13px; border: 1px solid var(--line); }.duplicate-compare legend { padding: 0 5px; color: var(--ink-soft); font-size: .69rem; font-weight: 700; }.duplicate-compare fieldset label { display: inline-flex !important; margin-right: 18px; }
 .compare-table th, .compare-table td { vertical-align: top; }.compare-table label { display: inline-flex; flex-direction: row; align-items: center; gap: 6px; }.difference-mark, .match-mark { display: block; width: max-content; margin-top: 4px; padding: 2px 5px; font-size: .52rem; border-radius: 2px; }.difference-mark { color: var(--warning); background: var(--warning-pale); }.match-mark { color: var(--success); background: var(--success-pale); }
 .merge-preview { padding: 13px; color: var(--ink-soft); background: var(--surface-subtle); border-left: 3px solid var(--teal); font-size: .75rem; }.duplicate-compare > button { color: white; background: var(--teal-dark); border-color: var(--teal-dark); }
+.merge-summary-counts { margin: 0 0 12px; color: var(--muted); font-size: .72rem; font-weight: 700; }
+.toggle-matching-fields { display: inline-block; margin: 10px 0; padding: 6px 10px; color: var(--ink-soft); background: transparent; border: 1px solid var(--line-strong); border-radius: var(--radius); font-size: .68rem; font-weight: 700; cursor: pointer; }
+.toggle-matching-fields:hover { background: var(--surface-subtle); }
+.merge-record-preview { margin: 14px 0; padding: 13px; background: var(--surface-subtle); border: 1px solid var(--line); border-radius: var(--radius); }
+.merge-record-preview-title { margin: 0 0 8px; color: var(--ink); font-size: .72rem; font-weight: 700; }
+.merge-record-preview dl { margin: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 6px 16px; }
+.merge-record-preview dt { margin: 0; color: var(--muted); font-size: .62rem; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; }
+.merge-record-preview dd { margin: 1px 0 0; color: var(--ink); font-size: .78rem; }
 .confirm-bar { margin-top: 13px; padding: 15px; background: var(--warning-pale); border: 1px solid #eed4aa; }.confirm-bar p { margin: 0 0 11px; color: #75420c; font-size: .75rem; font-weight: 700; }.confirm-bar button:first-of-type { color: white; background: var(--critical); border-color: var(--critical); }
 .resolution-actions { display: flex; gap: 9px; }.evidence-block { max-width: 100%; padding: 13px; overflow: auto; color: #324054; background: var(--surface-subtle); border: 1px solid var(--line); font-size: .68rem; }
 .evidence-disclosure { margin-top: 14px; }.evidence-disclosure summary { font-size: .68rem; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; }.evidence-disclosure .evidence-block { margin-top: 8px; }