This adds crate-level and type-level Rustdoc to the runtime crate's core exported types so downstream crates and contributors can understand the session, prompt, permission, OAuth, usage, and tool I/O primitives without spelunking every implementation file.
Constraint: The docs pass needed to stay focused on public runtime types without changing behavior
Rejected: Add blanket docs to every public item in one sweep | larger churn than needed for a targeted docs pass
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: When exporting new runtime primitives from lib.rs, add a short Rustdoc summary in the defining module at the same time
Tested: cargo build --workspace; cargo test --workspace
Not-tested: rustdoc HTML rendering beyond doc-test coverage
The Rust CLI/runtime now models permissions as ordered access levels, derives tool requirements from the shared tool specs, and prompts REPL users before one-off danger-full-access escalations from workspace-write sessions. This also wires explicit --permission-mode parsing and makes /permissions operate on the live session state instead of an implicit env-derived default.
Constraint: Must preserve the existing three user-facing modes read-only, workspace-write, and danger-full-access
Constraint: Must avoid new dependencies and keep enforcement inside the existing runtime/tool plumbing
Rejected: Keep the old Allow/Deny/Prompt policy model | could not represent ordered tool requirements across the CLI surface
Rejected: Continue sourcing live session mode solely from RUSTY_CLAUDE_PERMISSION_MODE | /permissions would not reliably reflect the current session state
Confidence: high
Scope-risk: moderate
Reversibility: clean
Directive: Add required_permission entries for new tools before exposing them to the runtime
Tested: cargo fmt; cargo clippy --workspace --all-targets -- -D warnings; cargo test -q
Not-tested: Manual interactive REPL approval flow in a live Anthropic session
