docs: final documentation consolidation - one canonical doc set

Audited every *.md in docs/ and root. Merged five overlapping backend
docs (BACKEND_INTEGRATION.md + AUTHENTICATION.md + ERROR_CONTRACT.md +
MAINTENANCE_MODE.md + the already-archived BACKEND_API.md/
BACKEND_API_REMAINING_WORK.md) into one canonical docs/BACKEND.md
(4775 lines, 10 numbered sections) - deleted the four standalone
files outright now that their content is fully inlined.

Archived (not deleted - real historical value): ADMIN.md (Sprint
19-28 build log, sprint-report-shaped, not a living reference) and
FRONTEND-ROADMAP.md (despite its name, a shipped-history changelog
with detail no other doc has - not a forward roadmap, so keeping it
in root alongside NEXT_PHASE.md was exactly the "10 roadmaps"
confusion being cleaned up).

Deleted outright (zero value): SPRINTS.md - a leftover copy-pasted
sprint-kickoff prompt saved as a file, not documentation.

Rewrote docs/PROJECT_STATUS.md with completion-percentage estimates
per area (frontend/backend/UI/admin/storefront) and an explicit
first-customer-readiness call. Rewrote docs/NEXT_PHASE.md to the
strict 5-phase structure (backend integration -> production testing
-> performance -> monitoring -> v2 ideas), pointing to PRODUCT_BACKLOG
.md/FUTURE_FEATURES.md for phase 5 detail instead of duplicating it.

Rewrote root README.md - was stale (referenced deleted pages/info,
pages/legal folders from a prior RC pass), now covers architecture,
frontend/backend status, how to run, mock<->API switch mechanism
(useMockData in environment.ts), current folder structure, and a
documentation map.

Updated docs/PROJECT_INDEX.md (the stated entry point) to link only
the surviving doc set - every remaining document is reachable from it.

Fixed every broken/stale cross-reference to the deleted/renamed
backend docs across ARCHITECTURE.md, EDITOR.md, FRONTEND.md,
PROJECT-STRUCTURE.md, StaticPages.md, KNOWN-ISSUES.md (10 individual
link fixes, verified by repo-wide grep before and after). Left
CHANGELOG.md's two historical entries untouched - changelogs are
append-only history, not live navigation, editing past entries would
misrepresent what was true at the time.

Not touched (explicitly out of scope): docs/architecture/foundation/**
(enforced ADRs/governance, permanent not sprint-shaped),
docs/context/** (Barry Cache infrastructure, "do not edit by hand"
per CLAUDE.md), .claude/worktrees/** (separate git worktrees
containing an unrelated project's docs, not this repo's documentation).

docs/ root: 22 files -> 16. Plus 5 in docs/archive/ (was 3).

docs/PROJECT_INDEX.md

@@ -18,7 +18,7 @@ Every tenant has three surfaces on this one codebase:
 - **Rendering**: Bootstrap JSON → Section Engine → Page Renderer → Widget Host → registered widget component (ADR-005). 100% lazy-loaded routes.
 - **Theming**: CSS custom properties per tenant, 3 theme stylesheets, never hardcoded hex in a component (ADR-008). Design system spec: [`DESIGN.md`](../DESIGN.md) (root of repo).
 - **i18n**: 3 locales (en/ru/hy), compile-time-enforced key parity across locale files.
-- **Backend**: mostly PLANNED (mock gateways behind swappable provider tokens) — see [BACKEND_INTEGRATION.md](BACKEND_INTEGRATION.md), the single canonical backend spec (endpoints, DTOs, auth, security, error model, uploads, migration guide, checklist). Categories is the one domain fully wired to a real HTTP gateway; everything else is local/mock.
+- **Backend**: mostly PLANNED (mock gateways behind swappable provider tokens) — see [BACKEND.md](BACKEND.md), the single canonical backend spec (architecture, bootstrap, auth, JWT, Ed25519, permissions, maintenance mode, error model, every endpoint, DTOs, uploads, pagination/filters/sorting, publish workflow, media, builder, implementation checklist). Categories is the one domain fully wired to a real HTTP gateway; everything else is local/mock.
 
 ## Doc index (living documents)
 
@@ -27,23 +27,18 @@ Read these directly — they're the current source of truth, not one-off reports
 | Doc | What it covers |
 |---|---|
 | [ARCHITECTURE.md](ARCHITECTURE.md) | Layered architecture, container/facade/service pattern, bootstrap/theme/widget engines, links to the enforced ADRs |
-| [BACKEND_INTEGRATION.md](BACKEND_INTEGRATION.md) | **Canonical backend spec** — every endpoint, DTO, CRUD contract, auth, security, error model, uploads, migration guide, checklist |
-| [AUTHENTICATION.md](AUTHENTICATION.md) | Standalone auth deep-dive (also inlined in BACKEND_INTEGRATION.md §4) |
-| [ERROR_CONTRACT.md](ERROR_CONTRACT.md) | Standalone error-contract deep-dive (also inlined in BACKEND_INTEGRATION.md §6) |
-| [MAINTENANCE_MODE.md](MAINTENANCE_MODE.md) | Global/tenant/module maintenance-mode contract |
+| [BACKEND.md](BACKEND.md) | **The one canonical backend spec** — auth, JWT, Ed25519, permissions, maintenance mode, every endpoint, DTOs, uploads, error model, migration guide, checklist |
 | [FRONTEND.md](FRONTEND.md) | App structure, routing, i18n, theming, state management, dynamic rendering |
 | [EDITOR.md](EDITOR.md) | The Project Editor: every section, save/publish/draft/reset model |
 | [StaticPages.md](StaticPages.md) | The Static Pages CMS module (the thing that actually serves About/Contacts/etc. today) |
 | [PROJECT-STRUCTURE.md](PROJECT-STRUCTURE.md) | Folder-by-folder tour of `src/app/**` with a worked feature-add example |
-| [ADMIN.md](ADMIN.md) | Admin backoffice: routing, architecture, data sources |
-| [PROJECT_STATUS.md](PROJECT_STATUS.md) | **Final Release Candidate status** — frontend/backend/docs/auth/builder/storefront/admin readiness, honest limitations |
-| [FRONTEND-ROADMAP.md](FRONTEND-ROADMAP.md) | Status snapshot refreshed from recent commits — what shipped, what's open |
+| [PROJECT_STATUS.md](PROJECT_STATUS.md) | **Current status** — completion %, readiness for demo/production/backend, honest limitations |
+| [NEXT_PHASE.md](NEXT_PHASE.md) | The one roadmap — backend integration → testing → performance → monitoring → v2 ideas |
+| [TODO.md](TODO.md) | Release blockers only — currently empty |
 | [KNOWN-ISSUES.md](KNOWN-ISSUES.md) | Real, reproducible, currently-open frontend bugs only |
 | [PRODUCT_BACKLOG.md](PRODUCT_BACKLOG.md) | Items needing a client/business decision (dark mode, brand colors, page content, etc.) |
 | [FUTURE_FEATURES.md](FUTURE_FEATURES.md) | Nice-to-have, non-blocking future work (Angular 22, bundle splitting, etc.) |
-| [NEXT_PHASE.md](NEXT_PHASE.md) | What happens after backend integration lands |
-| [TODO.md](TODO.md) | Release blockers only — currently empty |
-| [ANGULAR22_PLAN.md](ANGULAR22_PLAN.md) | Angular 22 upgrade feasibility (research only, not yet executed) |
+| [ANGULAR22_PLAN.md](ANGULAR22_PLAN.md) | Angular 22 upgrade feasibility (research only, not yet executed — tracked in FUTURE_FEATURES.md) |
 | [SALES-GUIDE.md](SALES-GUIDE.md) | Plain-language guide for the sales team — what to demo, what's not live yet |
 | [`../DESIGN.md`](../DESIGN.md) | Visual design system: colors, typography, elevation, component specs |
 | [`../PRODUCT.md`](../PRODUCT.md) | Product positioning, users, brand personality, anti-references |
@@ -52,7 +47,7 @@ Read these directly — they're the current source of truth, not one-off reports
 | `docs/context/**` | Barry Cache's own source-backed memory system — infrastructure, not project documentation, do not edit by hand |
 | `docs/archive/**` | Superseded docs, kept for history only — do not implement against these |
 
-**One topic, one place**: routing lives in FRONTEND.md, not repeated here. Backend contract lives in BACKEND_INTEGRATION.md, not repeated in ADMIN.md. Design tokens live in DESIGN.md, not repeated elsewhere.
+**One topic, one place**: routing lives in FRONTEND.md, not repeated here. Backend contract lives entirely in BACKEND.md — nowhere else. Design tokens live in DESIGN.md, not repeated elsewhere.
 
 ## What's still open
 
@@ -60,7 +55,7 @@ Read these directly — they're the current source of truth, not one-off reports
 
 ## Historical reports
 
-19 one-off audit/sprint/review reports were archived, then deleted once every open finding worth keeping was confirmed merged into [KNOWN-ISSUES.md](KNOWN-ISSUES.md)/[FRONTEND-ROADMAP.md](FRONTEND-ROADMAP.md)/[TODO.md](TODO.md). Full original text recoverable via `git log --diff-filter=D -- docs/archive` if needed.
+19 one-off audit/sprint/review reports were archived, then deleted once every open finding worth keeping was confirmed merged into [KNOWN-ISSUES.md](KNOWN-ISSUES.md)/[TODO.md](TODO.md). A 20th (`FRONTEND-ROADMAP.md`, despite its name a shipped-history changelog, not a forward roadmap) was archived to `docs/archive/` on 2026-07-26 for the same reason. Full original text recoverable via `git log --diff-filter=D -- docs/archive` or `docs/archive/FRONTEND-ROADMAP.md` itself.
 
 ## How to run it
 
@@ -84,11 +79,11 @@ See root `CLAUDE.md` for the full Barry Cache workflow and memory policy.
 
 ## Current status
 
-- **Frontend**: ~96% of planned UI built. Storefront/Builder/Backoffice all have working UI; several polish/audit passes complete (see below).
-- **Backend**: in progress — mostly PLANNED/mock gateways, no confirmed live backend contract beyond auth/session and storefront reads. Categories is the one domain fully wired to a real gateway.
-- **Storefront polish, performance audit, WCAG 2.1 AA accessibility audit, release-candidate walkthrough**: all done — see [FRONTEND-ROADMAP.md](FRONTEND-ROADMAP.md) for the summary of each.
-- **Angular 22 upgrade**: not started, feasibility researched — see [ANGULAR22_PLAN.md](ANGULAR22_PLAN.md) (verdict: safe, ~2-3.5 days, 2 tooling blockers to clear first).
-- **Documentation**: consolidated (this pass) — 19 one-off reports archived, 2 files renamed for clarity (`PROJECT.md`→`PROJECT_INDEX.md`, `backend/BACKEND-INTEGRATION.md`→`BACKEND_API.md`), 1 duplicate deleted (`RELEASE-NOTES.md` merged into `CHANGELOG.md`).
-- **First client demo**: upcoming — blocked on nothing documentation can fix; see [KNOWN-ISSUES.md](KNOWN-ISSUES.md) for what's still open, starting with the dead-routes finding at the top of this document.
+Full detail (completion %, per-area readiness, known limitations): [PROJECT_STATUS.md](PROJECT_STATUS.md). Short version:
 
-Draft/publish for the Project Editor is still **frontend-only** (localStorage), no backend persistence — the single largest backend gap, see [BACKEND_INTEGRATION.md §1 (Bootstrap: Draft vs Published)](BACKEND_INTEGRATION.md#1-bootstrap) and §8 (Real Backend Implementation Guide).
+- **Frontend**: Release Candidate, feature-complete. `TODO.md` has no blockers.
+- **Backend**: not implemented, fully specified. Categories is the one domain wired to a real gateway; everything else is mock. See [BACKEND.md](BACKEND.md).
+- **Documentation**: consolidated (Final Documentation Consolidation pass, 2026-07-26) — one canonical backend doc, one roadmap, one status doc, historical/sprint docs moved to `docs/archive/`.
+- **First client demo**: ready, with one caveat — admin role enforcement doesn't exist yet, see `PROJECT_STATUS.md`.
+
+Draft/publish for the Project Editor is still **frontend-only** (localStorage), no backend persistence — the single largest backend gap, see [BACKEND.md §1 (Bootstrap: Draft vs Published)](BACKEND.md#1-bootstrap) and §8 (Real Backend Implementation Guide).