feat(auto): wire driver selection through capabilities

skills/auto/SKILL.md

@@ -9,6 +9,8 @@ mcp_args:
   max_interview_rounds: "$max_interview_rounds"
   max_repair_rounds: "$max_repair_rounds"
   skip_run: "$skip_run"
+  driver: "$driver"
+  brake: "$brake"
 ---
 
 # /ouroboros:auto
@@ -30,6 +32,7 @@ is unavailable. A manual fallback is not an `ooo auto` run.
 ooo auto "Build a local-first habit tracker CLI"
 ooo auto --resume auto_abc123
 ooo auto "Build a local-first habit tracker CLI" --skip-run
+ooo auto "Build a local-first habit tracker CLI" --driver hermes --brake on
 /ouroboros:auto "Build a local-first habit tracker CLI"
 ```
 
@@ -42,3 +45,10 @@ ooo auto "Build a local-first habit tracker CLI" --skip-run
 5. Starts execution only after A-grade.
 
 The pipeline must not hang indefinitely: all loops are bounded and timeout failures return a resumable `auto_session_id`. Resume with `ooo auto --resume <auto_session_id>`. Use `--skip-run` to stop after the A-grade Seed. The CLI-only `--show-ledger` flag prints assumptions/non-goals; MCP skill responses already include the same ledger summary when available.
+
+When invoked through the interactive CLI without `--driver` or a configured
+default driver, `ooo auto` asks whether to use a selected interview driver if
+one of the supported driver CLIs is installed. Declining that prompt, or having
+no installed driver CLI, keeps the deterministic auto answerer. Use
+`--driver <backend>` to select a driver explicitly; use `--brake on|off` to
+control whether risky driver answers block for approval.

src/ouroboros/auto/__init__.py

@@ -6,7 +6,7 @@
 before starting execution.
 """
 
-from ouroboros.auto.answerer import AutoAnswer, AutoAnswerer, AutoAnswerSource
+from ouroboros.auto.answerer import AutoAnswer, AutoAnswerer, AutoAnswerMetadata, AutoAnswerSource
 from ouroboros.auto.grading import GradeGate, GradeResult, SeedGrade
 from ouroboros.auto.interview_driver import AutoInterviewDriver, AutoInterviewResult, InterviewTurn
 from ouroboros.auto.ledger import LedgerEntry, LedgerSection, SeedDraftLedger
@@ -17,6 +17,7 @@
 
 __all__ = [
     "AutoAnswer",
+    "AutoAnswerMetadata",
     "AutoAnswerSource",
     "AutoAnswerer",
     "AutoInterviewDriver",

src/ouroboros/auto/answerer.py

@@ -18,6 +18,7 @@ class AutoAnswerSource(StrEnum):
     EXISTING_CONVENTION = "existing_convention"
     CONSERVATIVE_DEFAULT = "conservative_default"
     ASSUMPTION = "assumption"
+    DRIVER = "driver"
     NON_GOAL = "non_goal"
     BLOCKER = "blocker"
 
@@ -64,6 +65,15 @@ class AutoBlocker:
     question: str
 
 
+@dataclass(frozen=True, slots=True)
+class AutoAnswerMetadata:
+    """Structured provenance for auto answers that need audit context."""
+
+    risk: str | None = None
+    confidence: float | None = None
+    provenance: tuple[str, ...] = ()
+
+
 @dataclass(frozen=True, slots=True)
 class AutoAnswer:
     """Answer plus structured ledger updates."""
@@ -75,6 +85,7 @@ class AutoAnswer:
     assumptions: list[str] = field(default_factory=list)
     non_goals: list[str] = field(default_factory=list)
     blocker: AutoBlocker | None = None
+    metadata: AutoAnswerMetadata = field(default_factory=AutoAnswerMetadata)
 
     @property
     def prefixed_text(self) -> str: