tinyagents-hooks: new crate holding every hook type #470

OpenHuman wants every hook to live in the harness (from openhuman#7929). Create crates/tinyagents-hooks. It depends on tinyagents-harness, and tinyagents-runtime depends on it.

Contents

• tool/: a typed in-process ToolHook<Ctx> (before_tool_decision / before_tool / after_tool / after_tool_context), ToolHookContext, ToolHooksMiddleware<Ctx>, a HookIdentity extractor trait (session_id, agent_id, cwd) and sanitize_tool_output.
  • One ToolHookDecision type, unified with the command-hook allow / deny / ask / updated_input / additional_context vocabulary.
  • Source: OpenHuman agent/hooks.rs (383 lines) and agent/tinyagents/middleware/embedder_hooks.rs (258).
• command/: move tinyagents-runtime/src/command_hooks/ here. It is self-contained and imports only super::.
  • HookEngine implements ToolHook directly.
  • Absorb the derived-event mapping from OpenHuman src/hooks/bridge.rs (373) and the lifecycle entry points session_started, prompt_submitted, pre_compact and subagent_* from src/hooks/ops.rs (263).
• stop/: move harness/src/middleware/library/stop_hooks/ and stop_latch.rs here, along with impl StopHookMetrics for TurnCost.
  • Add a stock BudgetStopHook (OpenHuman agent/stop_hooks.rs) and GoalBudgetStopHook (OpenHuman agent/goals/runtime.rs, taking Arc<dyn Store>, behind a goals feature).
  • Add StopHookMiddleware::with_halt_summary(slot) (OpenHuman agent/tinyagents/stop_hooks.rs).
• lifecycle/: move harness/src/middleware/library/lifecycle_hooks/ here.
• turn/: post-turn hooks folded into LearningSink.
  • Extend TurnSummary with per-tool outcome records: name, args digest, success, classified failure, duration.
  • Add parallel fire_* dispatch.
  • This replaces OpenHuman's PostTurnHook/TurnContext.
• scope.rs: HookScope, the per-turn tool, learning and stop hook lists (OpenHuman agent/hooks_scope.rs). Also add FnSessionHooks<C>, a closure-backed SessionHooks (OpenHuman agent/session_host/hooks.rs).

Compat

• tinyagents-runtime re-exports command_hooks for one release.
• Moving the harness middleware::StopHook paths is a breaking change: bump the minor version, add a CHANGELOG entry, and add docs/modules/hooks/README.md.
• Add the crate to the workspace default-members.

Done when: merged upstream with tests in sibling *_tests.rs, released or tagged, and the OpenHuman follow-up can delete the host copy after a gitlink bump on vendor/tinyagents.

Parent: tinyhumansai/openhuman#7929, which has the full file-by-file verdict tables.