Split monolithic pages (DebugPage 1.9k, PalettePage 1.8k, MapPage 1.3k lines) + SpecTabs tag-chip dedup

[MarkusNeusinger]

Medium#23 + Medium#14 from the 2026-07-08 audit:

• Three monolithic pages break the otherwise clean sections/ decomposition: DebugPage.tsx (~1,898 lines), PalettePage.tsx (~1,785 after the feat: legal-page links to kurrentschrift.ink & cite-citadel #9616 helpers extraction, which was lint-driven, not a decomposition), MapPage.tsx (~1,292). Extract sections/debug, sections/palette, sections/map with co-located tests, following the existing sections/ pattern.
• SpecTabs/index.tsx duplicates a ~50-line tag-chip rendering block (spec tags vs impl tags — blocks differ only in key prefix, param map, label formatting, and the !overviewMode guard). Extract a TagChipGroup component and render it twice.

Audit: agentic/audits/2026-07-08-product-ux.md (Medium#23 effort L, Medium#14 effort M).