Problem

crates/tui/src/hooks.rs is 2,576 lines mixing serde config types (HookEvent, matcher config, [[hooks.hooks]] shapes) with process execution, timeouts, and HookExecutor runtime behavior.

Hooks v2 contract work landed here; separating config from execution makes policy changes safer.

Proposed modules

• hooks/mod.rs — public API and re-exports.
• hooks/config.rs — events, matcher types, deserialization, validation.
• hooks/executor.rs — HookExecutor, subprocess IO, timeouts, decision JSON contract.
• hooks/matcher.rs (optional) — glob/path matching if separable from config.

Sizing

Acceptance criteria

• Config parsing/validation has no subprocess dependencies.
• Executor module owns all spawn/wait/timeout paths unchanged.
• Hooks v2 JSON decision contract tests keep passing.
• Run cargo fmt and targeted hooks tests.

Related: #1897, #3306, #3026.