Recover from an ambiguous push or Compile without stopping #56

After an ambiguous plan push or plan compile (request_outcome_unknown), the CLI's docs/errors.md tells the agent to stop until First Draft or an operator reconciles the Project. The user has no self-serve path.

The service already prevents duplicate work:

• A push or a Compilation start while a Compilation is active is refused with 409 compilation_active, which names the active Compilation and leads into the stuck-Compilation recovery.
• A rerun after the first Compilation finished makes a second direct Compilation. Its only effects are service compute and an unused retained artifact.

Proposal:

• An ambiguous Compile: rerun plan compile once, and follow a compilation_active refusal into recovery.
• An ambiguous push: initialize a new Project in a fresh folder and copy the Plan in. Projects are cheap in pre-alpha.

The CLI owns handled errors and recovery, so errors.md changes first and the Skill (firstdraft/skills) follows. Publication (--github) keeps its singleton rules.