Update V1 & V2 core documents and reorganize docs folder

docs/architecture.md

@@ -1,130 +0,0 @@
-# Architecture (V1 Baseline)
-
-This document describes the current architecture of the personal historical-document transcription system and serves as the V1 technical baseline.
-
-## Architecture Objectives
-
-- preserve source material as transcribed text
-- keep operational complexity low for personal-scale deployment
-- support asynchronous processing without external queue infrastructure
-- maintain clear module boundaries for incremental extension
-
-## Runtime Topology
-
-V1 runtime is a modular monolith:
-
-- one FastAPI + NiceGUI application process
-- one in-process async worker loop
-- relational persistence via SQLModel (SQLite baseline)
-
-```mermaid
-flowchart LR
-    U[Browser User] --> A[FastAPI + NiceGUI App]
-    A --> W[In-process Worker]
-    A --> DB[(SQLite via SQLModel)]
-    W --> P[OpenRouter Provider]
-    W --> DB
-```
-
-## Lifecycle Ownership
-
-Application lifespan owns runtime setup/teardown:
-
-- configure logging
-- initialize and dispose DB runtime resources
-- optional schema bootstrap by environment policy
-- recover stale processing jobs
-- start/stop worker consumer lifespan
-
-## Layered Module Structure
-
-### Interface Layer
-
-- `src/transcription/ui/**` (NiceGUI pages/components)
-- `src/transcription/api/**` (FastAPI routes and error handlers)
-
-### Application/Workflow Layer
-
-- `src/transcription/services/workflows.py`
-- `src/transcription/worker.py`
-
-Responsibilities:
-
-- orchestration and status transitions
-- retry/timeout behavior
-- provider call coordination
-
-### Service Layer
-
-- `src/transcription/services/*.py`
-
-Responsibilities:
-
-- CRUD and transactional boundaries
-- domain-aligned persistence operations
-
-### Infrastructure Layer
-
-- `src/transcription/db/**` (runtime/session/bootstrap)
-- `src/transcription/providers/**` (OpenRouter adapter)
-
-## Processing Workflow
-
-1. User uploads a source file from the UI.
-2. App persists `Document`, `Job(queued)`, and `Source`.
-3. Worker claims next queued job and marks `processing`.
-4. Worker calls provider with prompt + source bytes.
-5. On success, app writes immutable `Job.text` and marks `transcribed`.
-6. On failure, app writes `Job.error_detail` and marks `failed`.
-7. UI exposes job detail, original transcription, and optional revision.
-
-## Domain Ownership Invariants
-
-- `Job.text` is immutable original provider output.
-- `Revision` is optional, user-authored, and linked to `Source`.
-- `Revision` does not overwrite original job transcription.
-- Status lifecycle is fixed to: `queued -> processing -> transcribed|failed`.
-
-## Data Model Summary
-
-- `Document` has many `Source` and many `Job`.
-- `Source` belongs to one `Document` and one `Job`.
-- `Source` has optional `Revision` (`0..1`) enforced by unique `revision.source_id`.
-
-## Simplicity Guardrails (V1)
-
-- no external queue/broker required
-- no search engine required
-- no distributed worker fleet required
-- keep provider integration behind adapter boundary
-
-## Extension Path
-
-### V1 (current)
-
-- SQLite baseline
-- OpenRouter provider
-- in-process worker
-- optional single revision workflow
-
-### V2 (planned)
-
-- PostgreSQL as relational baseline
-- optional MongoDB adjunct store for scoped use cases
-- migration-first schema evolution
-
-See [ver2/ver2.md](ver2/ver2.md) for roadmap details.
-
-## Test Strategy
-
-- unit tests for model/service behaviors
-- integration tests for upload/workflow reliability
-- UI integration tests for page/render contracts
-- external provider tests opt-in via marker/config
-
-## Related References
-
-- [index.md](index.md)
-- [requirements.md](requirements.md)
-- [schema.md](schema.md)
-- [error_handling.md](error_handling.md)