feat(ownership): complete ownership intelligence module

Sprints 0-8: Types, schema, KSEI parser, entity resolution, DB CRUD,
Bing API client, import pipeline, query commands, graph traversal,
changes diff, entity resolution CLI, FTS5 search.

- KSEI PDF parser (mutool stext + quick-xml, 99.2% accuracy)
- 7 query commands: ticker, entity, search, cross-holders, concentration, flow, releases
- Ownership graph with recursive CTE (ASCII tree + Graphviz DOT)
- Release diff/changes between KSEI snapshots
- Entity resolution CLI: unresolved, map, merge
- FTS5 trigram search on entity names
- Feature-gated under 'ownership' (default-on)
- 82 tests passing

docs/ARCHITECTURE.md

@@ -0,0 +1,94 @@
+# Architecture
+
+## Domain Map
+
+```
+┌─────────────────────────────────────────────────────────┐
+│                      CLI Layer                           │
+│  main.rs → cli/stocks.rs, cli/ownership.rs, cli/...     │
+│  Clap derive structs, command dispatch, arg validation   │
+└──────────────────────┬──────────────────────────────────┘
+                       │
+        ┌──────────────┼──────────────┐
+        │              │              │
+┌───────▼───────┐ ┌────▼────┐ ┌──────▼──────┐
+│  API Layer    │ │ Analysis│ │  Ownership  │
+│  (providers)  │ │  Module │ │   Module    │
+│               │ │         │ │             │
+│ MarketData    │ │ techni- │ │ SQLite DB   │
+│ Provider trait│ │ cal.rs  │ │ KSEI parser │
+│               │ │ signals │ │ Bing client │
+│ Yahoo (OHLCV) │ │ fund.rs │ │ entity res. │
+│ MSN (rich)   │ │         │ │ FTS5 search │
+└───────┬───────┘ └────┬────┘ └──────┬──────┘
+        │              │              │
+┌───────▼──────────────▼──────────────▼──────┐
+│              Output Layer                    │
+│  table.rs (comfy-table) │ json.rs (serde)   │
+└─────────────────────────────────────────────┘
+```
+
+## Provider Architecture
+
+### Dual Provider Model
+- **MSN Finance** — default provider. Rich data: quotes, fundamentals, profile, earnings, financials, sentiment, insights, news, screener. No history for IDX stocks.
+- **Yahoo Finance** — history fallback. Reliable OHLCV data via `/v8/finance/chart/`.
+
+### Hybrid History Strategy
+When `history_provider = auto` (default):
+1. Check if current provider supports `HistoryProvider` trait
+2. MSN doesn't → transparently fallback to Yahoo
+3. Log info message: `"history provider fallback active (msn -> yahoo)"`
+
+### Capability Gating
+```
+MarketDataProvider = QuoteProvider + FundamentalsProvider
+HistoryProvider    = separate trait, not all providers implement
+
+Factory functions:
+  default_provider(kind) → Box<dyn MarketDataProvider>
+  history_provider(kind, mode, verbose) → Result<(ProviderKind, Box<dyn HistoryProvider>)>
+```
+
+## Ownership Module (SQLite-backed)
+
+Unlike the `stocks` module (live-fetch), ownership is **import-then-query**:
+
+1. `idx ownership import` — ETL pipeline: fetch PDF/API → parse → normalize → load SQLite
+2. All query commands read from local `~/.local/share/idx/ownership.db`
+3. Fully offline after import
+
+### Data Sources
+- **KSEI** — official ≥1% shareholder registry (monthly PDF from IDX)
+- **Bing Finance** — global institutional ownership (REST API, quarterly)
+
+### Parser Pipeline
+```
+KSEI PDF → mutool stext (XML with coordinates) → quick-xml parse → KseiRawRow
+  → normalize (ID locale numbers, dates, entity names) → KseiHolding
+  → SQLite INSERT (within transaction)
+```
+
+## Data Flow Patterns
+
+### Live Query (stocks module)
+```
+CLI args → resolve symbol → provider.quote/history/fundamentals → render table/json
+```
+
+### Import-Query (ownership module)
+```
+Import: PDF/API → parse → normalize → resolve entities → SQLite INSERT
+Query:  CLI args → SQLite SELECT → render table/json (no network)
+```
+
+## Configuration Precedence
+```
+CLI flags > environment variables > config file > defaults
+```
+
+## Error Strategy
+- `IdxError` enum (thiserror) with structured error codes
+- Table mode: human-readable error on stderr
+- JSON mode: `{"error": true, "code": "...", "message": "..."}`
+- Exit code 0 on success, non-zero on failure