docs: integrate root ROADMAP.md into docs/ROADMAP.md

Merge the tactical root ROADMAP.md (SOLIDWORKS PDM gap analysis, Phase 1-6
timelines, project inventory) with the visionary docs/ROADMAP.md (modular
platform architecture, .kc format, dependency tiers) into a single unified
document at docs/ROADMAP.md.

- Adopt dependency tier structure (Tier 0-6) as the organizing spine
- Add Status column to each tier table from project inventory
- Replace Phase 1-6 calendar timelines with Near-Term Priorities section
- Migrate 9 SOLIDWORKS PDM comparison tables to docs/GAP_ANALYSIS.md
- Migrate Feature Comparison Matrix to docs/GAP_ANALYSIS.md
- Preserve Phase 1 task checklists and success metrics as appendices
- Update README.md link from ROADMAP.md to docs/ROADMAP.md
- Delete root ROADMAP.md

README.md

@@ -118,7 +118,7 @@ The server provides the REST API and ODS endpoints consumed by these clients.
 | [docs/AUTH_USER_GUIDE.md](docs/AUTH_USER_GUIDE.md) | User guide for login, tokens, and roles |
 | [docs/GAP_ANALYSIS.md](docs/GAP_ANALYSIS.md) | Gap analysis and revision control roadmap |
 | [docs/COMPONENT_AUDIT.md](docs/COMPONENT_AUDIT.md) | Component audit tool design |
-| [ROADMAP.md](ROADMAP.md) | Feature roadmap and SOLIDWORKS PDM comparison |
+| [docs/ROADMAP.md](docs/ROADMAP.md) | Platform roadmap, dependency tiers, and gap summary |
 | [frontend-spec.md](frontend-spec.md) | React SPA frontend specification |
 
 ## License