Align target (targets.yaml) workspace-setup hooks with the eval workspace hook model #1391

Objective

Follow-up to #1389. The eval workspace: block was cleaned up (repos = provenance, acquisition = harness resolver, hooks: unchanged). But targets.yaml also carries workspace-setup hooks (TargetHooksConfig: before_all/before_each/after_each/after_all), and that surface was deliberately untouched by #1389. Audit and align it with the eval workspace hook model so the two stay consistent.

Background (current state)

• WorkspaceHooksConfig (eval workspace.hooks) and TargetHooksConfig (per-target hooks) are two parallel types with the same four lifecycle keys, both using WorkspaceHookConfig for the command/cwd/env shape (packages/core/src/evaluation/types.ts).
• Documented execution order: workspace before_all → target before_all → (per test: workspace before_each → target before_each); teardown mirrored.
• Targets have no repos — repo provenance lives only in the shared eval workspace. Targets get cwd/workspaceFile resolved from the eval workspace.template and customize it via setup hooks (the "harness variant" pattern).

Scope to resolve

1. Schema parity / dedup — should TargetHooksConfig and WorkspaceHooksConfig be unified (one hooks type) or kept distinct? If distinct, document why; if unified, do it non-breakingly.
2. Context semantics parity — confirm target hooks receive the same workspace context (stdin payload), cwd resolution, and env-merge semantics as workspace hooks; fix any divergence.
3. Affirm the boundary — explicitly document that targets do NOT declare repos (provenance stays in the shared workspace) so it isn't mistaken for a gap. Decide whether a target ever needs repo-level overrides (likely no — YAGNI).
4. Docs + examples — ensure the lifecycle ordering and target-hook usage are documented on agentv.dev and reflected in the generated schema; update any examples.

Non-goals

• No new repo/acquisition fields on targets.
• No change to the Collapse repo source schema to provenance + acquisition resolver #1389 eval-workspace schema.

Related

• Collapse repo source schema to provenance + acquisition resolver #1389 (eval workspace provenance/acquisition split), PR feat(workspace): split repo provenance from acquisition #1390
• Code: packages/core/src/evaluation/types.ts (TargetHooksConfig, WorkspaceHooksConfig, WorkspaceHookConfig), target hook execution in the orchestrator