Mirador UI v1.1 — Industrial pass

Code reductions (~4 500 LOC net removed):
* ADR-0008 retire Observability page → Grafana Explore deep-link (MR 1)
* Dashboard lean: drop error timeline, sparkline, bundle treemap, customer stat (MR 2)
* About trim: 2 900 → 577 lines, tab prose → docs/architecture/*.md (MR 3)
* ADR-0009 Phase A: TelemetryService + custom AppErrorHandler (MR 4)
* ADR-0009 Phase B: OTel Web SDK exporter → OTLP :4319 (MR 30)

Docs + ops:
* ROADMAP.md — unvalidated Tier 1/2/3 industrial proposals
* CLAUDE.md — HH:MM time rule, session-start budget check
* README badges grouped by concern
* banner SVG refresh

Bundle impact: about 124 → 58 kB (-53%), dashboard 72 → 62 kB (-15%),
observability chunk gone. Initial total 522 kB (OTel SDK raises budget
560 → 800 kB, still well under 1 MB error ceiling).

Paired release: mirador-service v1.1.