fix(review): restore CodeReview/DeepReview session creation and turns

[YodonTan]

Problem

Entering /review in the input box fails immediately with:

Failed to create session: Validation error: Unknown session mode: CodeReview

The review child session (agentType=CodeReview for standard review, DeepReview for strict) can no longer be created or run.

Root cause

resolve_primary_agent_for_turn (registry) only accepted AgentCategory::Mode entries in its local fallback, but CodeReview is registered as a SubAgent and DeepReview as Hidden. Session creation, turn start, manual compaction, and session restore all funnel through this resolution, so:

• /review fails at child-session creation;
• persisted review sessions could be silently rewritten to agentic on restore.

Regression introduced by ca94825ad ("feat(extensions): activate external primary agent profiles"), which wired this Mode-only filter into the create/turn paths.

Fix

Allow the builtin CodeReview/DeepReview agents to resolve as local session primaries while keeping every other subagent (e.g. ReviewWorker) restricted, and add diagnostics at the rejection point (warn! when a registered non-mode agent is rejected, debug! when the id is unknown). The expected_owner == External fail-closed guard is unchanged.

Follow-up cleanup (2nd commit)

CODE_REVIEW_AGENT_TYPE constant introduced in agent-runtime::deep_review::constants and used in registry review-entry detection and session-primary resolution, replacing the scattered "CodeReview" magic string. This cleanup also served as the verification content for the fix: it was written into a workspace, then reviewed end-to-end with the /review command after installing the fixed Windows build, confirming review sessions create and run correctly.

Tests

• agentic::agents::registry::tests::builtin_review_agents_resolve_as_local_session_primaries — CodeReview/DeepReview resolve with route owner Local.
• agentic::agents::registry::tests::non_session_primary_subagents_and_unknown_ids_do_not_resolve — ReviewWorker / unknown ids / external-owner guard stay rejected.
• agentic::coordination::coordinator::tests::review_agent_child_sessions_create_successfully — coordinator-level session creation for both agent types.

All existing registry (33), coordinator (94), and session-manager (136) tests pass; cargo check -p bitfun-core --no-default-features is clean.

Closes #2100

[limityan]

resolve_primary_agent_for_turn 的修复目前只覆盖了无 workspace external route 时的 fallback 分支。命中 ExternalSubagentRoute::Local 时（external.rs 约 439–442 行），代码仍只接受 AgentCategory::Mode，而内置 CodeReview / DeepReview 并非 Mode，因此显式选择 Local route 的 workspace 仍可能在创建、恢复或启动 review session 时失败。

建议提取统一的 local session-primary 判定，并同时用于 ExternalSubagentRoute::Local 与 fallback 两个分支；另外增加安装 CodeReview -> Local route 后仍能成功解析的测试。

[YodonTan]

Thanks for the review — you are right. The fix only covered the no-route fallback; the \ExternalSubagentRoute::Local\ branch (workspaces where a same-name conflict was explicitly resolved to the local candidate) still filtered to \AgentCategory::Mode\ and would reject CodeReview/DeepReview.

Addressed in \c02740ad3:

• Extracted a shared \is_local_session_primary_entry\ predicate (Mode or builtin session-primary) now used by both the explicit Local-route branch and the no-route fallback, so both paths behave identically.
• The Local-route branch now emits the same diagnostic \warn!\ as the fallback when a registered entry is rejected.
• Added \local_route_resolves_review_agents_as_session_primaries: with CodeReview/DeepReview/ReviewWorker pinned to \ExternalSubagentRoute::Local, the review agents resolve with route owner Local while ReviewWorker stays rejected.

Registry suite: 34 passed (33 existing + 1 new). \cargo check -p bitfun-core --no-default-features\ clean.

[limityan]

已重新审核最新提交。

上次提出的问题已修复：

• ExternalSubagentRoute::Local 与无路由 fallback 现在共用 is_local_session_primary_entry；
• CodeReview / DeepReview 使用统一的运行时常量；
• 新增显式 Local route 的 registry 测试，并确认 ReviewWorker 仍被拒绝；
• 相关 review agent 标识也完成了常量化，避免继续散落 magic string；
• GitHub CI 的 7 项检查全部通过。

未发现新的阻塞性问题，批准合并。