diff --git a/docs/README.md b/docs/README.md
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+<!--══════════════════════════════════════════════════════════
+  ╔══════════════════════════════════════════════════════════════╗
+  ║  ░  D O C S   I N D E X  ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░  ║
+  ║                                                              ║
+  ║                                                              ║
+  ║                                                              ║
+  ║                                                              ║
+  ║           ╌╌  P L A C E H O L D E R  ╌╌                      ║
+  ║                                                              ║
+  ║                                                              ║
+  ║                                                              ║
+  ║                                                              ║
+  ╚══════════════════════════════════════════════════════════════╝
+    • WHAT ▸ Overview and folder purposes for documentation
+    • WHY  ▸ Keep navigation clear; avoid duplication and drift
+    • HOW  ▸ Short descriptions + links to canonical locations
+-->
+
+## Folder purposes
+
+- Root (this folder)
+  - Top‑level product/plan docs and indices: `PRD.md`, `implementation.md`, `system_principles.md`, `project_structure.md`, `backlog.md`. Start here for the current plan and principles.
+
+- `architecture/`
+  - System design and C4 views. Use `README.md` for the overview; `C1-context.md`, `C2-containers.md`, `C3-components.md` for deeper levels. ADRs live separately under `adr/`.
+
+- `adr/`
+  - Architectural Decision Records. Each ADR is a permanent, numbered record that links PRD requirements to code paths and consequences.
+
+- `guide/`
+  - Developer‑facing guidance using Diátaxis:
+    - `how-to/` — step‑by‑step tasks (web demo server, mac app details, etc.)
+    - `tutorials/` — learn by doing (try MindTyper in 5 min)
+    - `reference/` — APIs and contracts (band policy, injector, LM behavior, worker, rust merge, config flags)
+    - `explanations/` — deeper rationale (e.g., why caret‑safe diffs)
+
+- `qa/`
+  - Quality gates and acceptance (BDD) scenarios; matrix mapping in `qa/README.md`.
+
+- `a11y/`
+  - Accessibility standards and checklists.
+
+- `brand/`
+  - Brand assets, specs, and guides (visual identity, tone, motion). Not product behavior.
+
+- `questionnaire/`
+  - Product questionnaire sections and live `questions.md` (clarifications). Treat as the primary Q&A surface; deprecated `questions-incomplete.md` has been removed.
+
+## Conventions
+
+- One canonical home per topic; avoid duplicates. If two docs drift or overlap, merge or link — don’t fork.
+- Cross‑link related content (PRD ↔ ADR ↔ architecture ↔ guides ↔ QA) for traceability.
+- Keep Swiss‑grid headers; prefer concise files with hyperlinks over long monoliths.
diff --git a/docs/a11y/README.md b/docs/a11y/README.md
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+<!--══════════════════════════════════════════════════════════
+  ╔══════════════════════════════════════════════════════════════╗
+  ║  ░  A 1 1 Y   I N D E X  ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░  ║
+  ║                                                              ║
+  ║  Accessibility docs and checklists (WCAG 2.2 AA).            ║
+  ║                                                              ║
+  ╚══════════════════════════════════════════════════════════════╝
+    • WHAT ▸ Centralize accessibility standards and audits
+    • WHY  ▸ Enforce inclusive defaults across product
+    • HOW  ▸ Keep concise checklists + links to specs
+-->
+
+- Checklist: `wcag-checklist.md`
+- Principles: respect reduced motion; never rely on color/motion alone; SR announces via `ui/liveRegion.ts`.
diff --git a/docs/guide/README.md b/docs/guide/README.md
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+<!--══════════════════════════════════════════════════════════
+  ╔══════════════════════════════════════════════════════════════╗
+  ║  ░  G U I D E S   I N D E X  ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░  ║
+  ║                                                              ║
+  ║  How‑to, tutorials, references, and explanations for devs.   ║
+  ║                                                              ║
+  ║                                                              ║
+  ║                                                              ║
+  ╚══════════════════════════════════════════════════════════════╝
+    • WHAT ▸ Diátaxis structure for developer docs
+    • WHY  ▸ Predictable navigation + single sources of truth
+    • HOW  ▸ Each subfolder has a clear purpose (below)
+-->
+
+## Structure
+
+- `how-to/` — Task‑oriented guides (e.g., web demo server, mac app details, fine‑tune Qwen).
+- `tutorials/` — Learn‑by‑doing walkthroughs (e.g., try MindTyper in 5 minutes).
+- `reference/` — Stable contracts and APIs (band policy, injector, LM behavior, worker, rust merge, config flags).
+- `explanations/` — Rationale and deep dives (e.g., why caret‑safe diffs).
+
+Rules:
+
+- If a document specifies “how”, it belongs in `how-to/`.
+- If it defines an API/contract/canonical behavior, it belongs in `reference/`.
+- If it teaches via a project, it belongs in `tutorials/`.
+- If it answers “why”, it belongs in `explanations/`.
diff --git a/docs/questionnaire/questions-incomplete.md b/docs/questionnaire/questions-incomplete.md
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-<!--══════════════════════════════════════════════════
-  ╔══════════════════════════════════════════════════════╗
-  ║  ░  QUESTIONS NEEDING MORE DETAIL — MINDTYPER  ░░░░░ ║
-  ║                                                      ║
-  ║              ╌╌  A L L   R E S O L V E D  ╌╌         ║
-  ║                                                      ║
-  ╚══════════════════════════════════════════════════════╝
-    • WHAT ▸ Track gaps that require precision before PRD/spec
-    • WHY  ▸ Prevent ambiguity in UX, security, and architecture
-    • HOW  ▸ Log here → implement in section files → update index
--->
-
-# Questions Needing More Detail — MindTyper
-
-All items below were implemented on 2025‑08‑08. See the linked files for details.
-
-- Undo grouping granularity: `02_user_research_ergonomics.md` and `05_input_handling_text_flow.md` (Clarifier 2.6.a / 5.6.a)
-- Personalization storage caps & compaction: `03_context_awareness_personalization.md` and `08_technical_architecture.md` (Clarifier 3.14.a / 8.14.a)
-- Sync encryption & key management: `07_model_adaptation_personalization.md` (Clarifier 7.4.a)
-- FFI error codes & sequence diagram: `08_technical_architecture.md` (Clarifier 8.6.a / 8.7.a)
-- Keychain failure & signature mismatch UX: `09_security_privacy.md` (Clarifier 9.3.a)
-- MAS vs direct revenue splits + blends: `10_business_strategy.md` (Clarifier 10.7.a)
-- CI performance budgets per job: `11_testing_qa.md` (Clarifier 11.3.a)
-- NSVisualEffectView materials map: `12_design_system.md` (Clarifier 12.2.b)
-- Product Hunt checklist + outreach: `13_launch_metrics.md` (Clarifier 13.4.a / 13.4.b)
diff --git a/docs/questions.md b/docs/questionnaire/questions.md
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rename to docs/questionnaire/questions.md