v6.3.0

• release: v6.3.0 metadata — v264 country-softguard (#1104) (3771c88)
• feat(train): country_ambiguous_scale softener → v264 (promote as v6.3.0) (#1130) (994f952)
• docs(reference): STAGES.mdx — resolve the jointReconcile default-vs-retired contradiction (#1129) (2de9860)
• docs: apply curated cross-link proposal (83 links, +10 doc-map bonus) (#1128) (98f0768)
• docs: light de-slop pass over understanding/, recipes/, and the maintained plan surface (#1127) (383cc85)
• docs: de-slop pass A — concepts, root articles, licensing (#1126) (4c6c415)
• feat(eval): gate --weights-cache (package-shaped) + ledger backfill 6.0-6.2 (#1125) (4fc7e15)
• docs: v263 recaptures + Step 5 checklist upgrades from its first field run (#1124) (5dc67f4)
• docs: Phase 4 — prevent relapse (policy page, structure gate, PR prompts, freshness sweep) (#1122) (c99dc2b)
• docs(releases): add 6.2.0 (v263 country channel) + 6.2.1 (browser) rows (404206e)
• docs(status): refresh to the shipped v263 / 6.2.x line (#1104 closed) (b980729)