docs: update CLAUDE.md files for EF Core migration

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

src/ClaudeDo.Data/CLAUDE.md

@@ -11,7 +11,7 @@ Shared data layer: models, repositories, SQLite infrastructure, and git operatio
 
 ## Repositories
 
-All repositories use raw parameterized SQL via `Microsoft.Data.Sqlite`. Each method opens its own connection — no Unit of Work.
+All repositories use EF Core LINQ queries via `ClaudeDoDbContext`. Exception: `TaskRepository.GetNextQueuedAgentTaskAsync` uses `FromSqlRaw` for atomic queue claim.
 
 - **TaskRepository** — CRUD, status transitions (`MarkRunningAsync`, `MarkDoneAsync`, `MarkFailedAsync`), `GetNextQueuedAgentTaskAsync` (queue polling), `GetEffectiveTagsAsync` (union of task + list tags), `FlipAllRunningToFailedAsync`
 - **ListRepository** — CRUD, tag junction management
@@ -20,8 +20,8 @@ All repositories use raw parameterized SQL via `Microsoft.Data.Sqlite`. Each met
 
 ## Infrastructure
 
-- **SqliteConnectionFactory** — creates connections, applies WAL mode once, enforces foreign keys via PRAGMA
-- **SchemaInitializer** — applies embedded `schema/schema.sql` idempotently (IF NOT EXISTS, INSERT OR IGNORE)
+- **ClaudeDoDbContext** — EF Core DbContext; configured with WAL mode and foreign keys via `UseSqlite` options
+- **IDbContextFactory<ClaudeDoDbContext>** — registered in DI; used by singleton consumers (e.g. Worker hosted service)
 - **Paths** — expands `~` and `%USERPROFILE%`, resolves relative paths. App root: `~/.todo-app`
 - **AppSettings** — loads `~/.todo-app/ui.config.json` (DbPath, SignalRUrl)
 
@@ -31,11 +31,11 @@ All repositories use raw parameterized SQL via `Microsoft.Data.Sqlite`. Each met
 
 ## Schema
 
-6 tables: `lists`, `tasks`, `tags`, `list_tags`, `task_tags`, `worktrees`. See `schema/schema.sql`. Seed data: tags "agent" and "manual".
+6 tables: `lists`, `tasks`, `tags`, `list_tags`, `task_tags`, `worktrees`. Managed by EF Core migrations in the `Migrations/` folder. Seed data: tags "agent" and "manual".
 
 ## Conventions
 
-- Enum <-> string mapping via explicit `ToDb()`/`FromDb()` static methods on each enum
+- Enum <-> string mapping via EF Core `ValueConverter` (configured in `IEntityTypeConfiguration<T>`)
+- Entity configurations live in the `Configuration/` folder
 - Primary keys are `init`-only strings (GUIDs assigned at creation)
-- Nullable fields use `DBNull.Value` checks
 - All methods are async with CancellationToken where applicable