docs: introduce bible/ as single source of architectural truth

- Add bible/ with 7 hierarchical English-only files covering overview,
  architecture, database schemas, API endpoints, config/env, backup, and dev guides
- Consolidate all docs from README.md, CLAUDE.md, man/backup.md into bible/
- Simplify CLAUDE.md to a single rule: read and respect the bible
- Simplify README.md to a brief intro with links to bible/
- Remove man/backup.md and pricelists_window.md (content migrated or obsolete)
- Fix API docs: add missing endpoints (preview-article, sync/repair),
  correct DELETE /api/projects/:uuid semantics (variant soft-delete only)
- Add Soft Deletes section to architecture doc (is_active pattern)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bible/01-overview.md

@@ -0,0 +1,119 @@
+# 01 — Product Overview
+
+## What is QuoteForge
+
+A corporate server configuration and quotation tool.
+Operates in **strict local-first** mode: all user operations go through local SQLite; MariaDB is used only for synchronization.
+
+---
+
+## Features
+
+### For Users
+- Mobile-first interface — works comfortably on phones and tablets
+- Server configurator — step-by-step component selection
+- Automatic price calculation — based on pricelists from local cache
+- CSV export — ready-to-use specifications for clients
+- Configuration history — versioned snapshots with rollback support
+- Full offline operation — continue working without network, sync later
+- Guarded synchronization — sync is blocked by preflight check if local schema is not ready
+
+### User Roles
+
+| Role | Permissions |
+|------|-------------|
+| `viewer` | View, create quotes, export |
+| `editor` | + save configurations |
+| `pricing_admin` | + manage prices and alerts |
+| `admin` | Full access, user management |
+
+### Price Freshness Indicators
+
+| Color | Status | Condition |
+|-------|--------|-----------|
+| Green | Fresh | < 30 days, ≥ 3 sources |
+| Yellow | Normal | 30–60 days |
+| Orange | Aging | 60–90 days |
+| Red | Stale | > 90 days or no data |
+
+---
+
+## Tech Stack
+
+| Layer | Stack |
+|-------|-------|
+| Backend | Go 1.22+, Gin, GORM |
+| Frontend | HTML, Tailwind CSS, htmx |
+| Local DB | SQLite (`qfs.db`) |
+| Server DB | MariaDB 11+ (sync + server admin) |
+| Export | encoding/csv, excelize (XLSX) |
+
+---
+
+## Product Scope
+
+**In scope:**
+- Component configurator and quotation calculation
+- Projects and configurations
+- Read-only pricelist viewing from local cache
+- Sync (pull components/pricelists, push local changes)
+
+**Out of scope (removed intentionally — do not restore):**
+- Admin pricing UI/API
+- Stock import
+- Alerts
+- Cron/importer utilities
+
+---
+
+## Repository Structure
+
+```
+quoteforge/
+├── cmd/
+│   ├── qfs/main.go               # HTTP server entry point
+│   ├── migrate/                  # Migration tool
+│   └── migrate_ops_projects/     # OPS project migrator
+├── internal/
+│   ├── appmeta/                  # App version metadata
+│   ├── appstate/                 # State management, backup
+│   ├── article/                  # Article generation
+│   ├── config/                   # Config parsing
+│   ├── db/                       # DB initialization
+│   ├── handlers/                 # HTTP handlers
+│   ├── localdb/                  # SQLite layer
+│   ├── lotmatch/                 # Lot matching logic
+│   ├── middleware/               # Auth, CORS, etc.
+│   ├── models/                   # GORM models
+│   ├── repository/               # Repository layer
+│   └── services/                 # Business logic
+├── web/
+│   ├── templates/                # HTML templates + partials
+│   └── static/                   # CSS, JS, assets
+├── migrations/                   # SQL migration files (30+)
+├── bible/                        # Architectural documentation (this section)
+├── releases/memory/              # Per-version changelogs
+├── config.example.yaml           # Config template (the only one in repo)
+└── go.mod
+```
+
+---
+
+## Integration with Existing DB
+
+QuoteForge integrates with the existing `RFQ_LOG` database:
+
+**Read-only:**
+- `lot` — component catalog
+- `qt_lot_metadata` — extended component data
+- `qt_categories` — categories
+- `qt_pricelists`, `qt_pricelist_items` — pricelists
+
+**Read + Write:**
+- `qt_configurations` — configurations
+- `qt_projects` — projects
+
+**Sync service tables:**
+- `qt_client_local_migrations` — migration catalog (SELECT only)
+- `qt_client_schema_state` — applied migrations state
+- `qt_pricelist_sync_status` — pricelist sync status