This threads typed hook settings through runtime config, adds a shell-based hook runner, and executes PreToolUse/PostToolUse around each tool call in the conversation loop. The CLI now rebuilds runtimes with settings-derived hook configuration so user-defined Claude hook commands actually run before and after tools.
Constraint: Hook behavior needed to match Claude-style settings.json hooks without broad plugin/MCP parity work in this change
Rejected: Delay hook loading to the tool executor layer | would miss denied tool calls and duplicate runtime policy plumbing
Confidence: medium
Scope-risk: moderate
Reversibility: clean
Directive: Keep hook execution in the runtime loop so permission decisions and tool results remain wrapped by the same conversation semantics
Tested: cargo test; cargo build --release
Not-tested: Real user hook scripts outside the test harness; broader plugin/skills parity
Add typed runtime-facing MCP and OAuth configuration models on top of the existing merged settings loader so later parity work can consume validated structures instead of ad hoc JSON traversal.
This keeps the first slice bounded to parsing, precedence, exports, and tests. While validating the slice under the repo's required clippy gate, I also fixed a handful of pre-existing clippy failures in runtime file operations so the requested verification command can pass for this commit.
Constraint: Must keep scope to parity-unblocking primitives, not full MCP or OAuth flow execution
Constraint: cargo clippy --all-targets is a required verification gate for this repo
Rejected: Add a new integrations crate first | too much boundary churn for the first landing slice
Rejected: Leave existing clippy failures untouched | would block the required verification command for this commit
Confidence: medium
Scope-risk: moderate
Reversibility: clean
Directive: Keep future MCP/OAuth additions layered on these typed config surfaces before introducing transport orchestration
Tested: cargo fmt --all; cargo test -p runtime; cargo clippy -p runtime --all-targets -- -D warnings
Not-tested: workspace-wide clippy/test beyond the runtime crate; live MCP or OAuth network flows
