fix(worker): normalize model alias before preset lookup, wire DefaultMaxTurns as fallback

A full model id like claude-sonnet-4-6 in list_config.model never matched any
ModelPresets row (only bare aliases did), so every run under it landed on the
hardcoded 30-turn/DefaultLevel fallback instead of the sonnet preset row -
this is what killed two autonomous tasks at the 30-turn limit.

ModelRegistry.TryNormalizeAlias (non-throwing: exact match, then substring
match against a full model id) lets ModelPresets.For resolve a full model id
to its alias's preset row. For a model that still doesn't resolve, the
hardcoded 30 is replaced by a caller-supplied fallbackMaxTurns, and TaskRunner
now passes AppSettings.DefaultMaxTurns there - so that setting has a real
effect instead of being dead, matching the direction already noted in
docs/open.md.

src/ClaudeDo.Data/CLAUDE.md

@@ -14,7 +14,8 @@ Shared data layer: models, repositories, SQLite infrastructure, and git operatio
 - **WeekReportEntity** — Id, StartDate/EndDate (DateOnly), Markdown, GeneratedAt → table `week_reports`, unique index on (start_date, end_date)
 - **TaskAttachmentEntity** — Id, TaskId (FK to tasks, ON DELETE CASCADE), FileName, ByteSize, CreatedAt → table `task_attachments`
 - **AppSettingsEntity** also carries `ReportExcludedPaths` (string?, JSON array of excluded path prefixes, column `report_excluded_paths`), `StandupWeekday` (int DayOfWeek, default Wednesday, column `standup_weekday`), and `DailyPrepMaxTasks` (int, default 5, column `daily_prep_max_tasks` — hard cap on how many open tasks the daily-prep / "Prime Claude" feature may place in MyDay) and `ModelPresets` (string?, JSON array of `ModelPreset` rows, column `model_presets`)
-- **ModelPresets** / **ModelPreset** — per-model run defaults (`Model`, `Effort`, `MaxTurns`): one row per `ModelRegistry.Aliases` entry, supplying the **global** effort and max-turns defaults. `Parse`/`Serialize` normalize (unknown models dropped, missing aliases filled from `Defaults`, effort validated, turns clamped 1–200) and never throw — a malformed settings row must not stop a run. `For(presets, model)` always returns a usable row. Ship defaults: haiku medium/20, sonnet high/30, opus high/40, fable high/25.
+- **ModelPresets** / **ModelPreset** — per-model run defaults (`Model`, `Effort`, `MaxTurns`): one row per `ModelRegistry.Aliases` entry, supplying the **global** effort and max-turns defaults. `Parse`/`Serialize` normalize (unknown models dropped, missing aliases filled from `Defaults`, effort validated, turns clamped 1–200) and never throw — a malformed settings row must not stop a run. `For(presets, model, fallbackMaxTurns = 30)` always returns a usable row: `model` is resolved through `ModelRegistry.TryNormalizeAlias` first, so a full CLI model id (e.g. `claude-sonnet-4-6`) still hits its alias's preset row instead of missing every lookup and falling through; only a model that normalizes to nothing recognized falls back to a synthesized row (`EffortRegistry.DefaultLevel` + `fallbackMaxTurns` — callers pass `AppSettings.DefaultMaxTurns` here so that setting has a real effect instead of a hardcoded number). Ship defaults: haiku medium/20, sonnet high/30, opus high/40, fable high/25.
+- **ModelRegistry.TryNormalizeAlias** — non-throwing counterpart to `NormalizeAlias` for the run path: exact alias match, then substring match against a full model id, else `null`. Never throws, unlike `NormalizeAlias` (which stays the strict, throwing validator for `add_task`/planning model input).
 - **EffortRegistry** — the `--effort` levels (`low|medium|high|xhigh|max`) + `NormalizeLevel` (blank → null = don't pass the flag)
 - **SubtaskEntity**, **AppSettingsEntity**, **AgentInfo** — existing helpers / settings / record for scanned agent files