Recursive shared-folder rule: a shared/ must be shared by ALL siblings at its
level. The kernel (context, compaction, retry_after, web_search) was shared by
only 2 of the agents -- anonymous_chat + multi_agent_chat -- never by podcaster
or video_presentation. Those 2 are the "chat" category, so their shared code
belongs in that category's shared/, not the top-level one.
app/agents/anonymous_chat/ -> app/agents/chat/anonymous_chat/
app/agents/multi_agent_chat/ -> app/agents/chat/multi_agent_chat/
app/agents/shared/ -> app/agents/chat/shared/ (anon<->mac kernel)
Top-level app/agents/shared/ is gone: nothing was shared across all three
categories (chat / podcaster / video_presentation).
~289 import sites rewritten (app.agents.{anonymous_chat,multi_agent_chat,shared}
-> app.agents.chat.*); all moves are git renames (history preserved).
app/agents/ now: chat/, podcaster/, video_presentation/, runtime/.
app/agents/shared/ is a sibling of anonymous_chat/podcaster/multi_agent_chat/
video_presentation, so it should only hold code shared across 2+ of those
agents. In practice podcaster and video_presentation import nothing from it,
and anonymous_chat needs only context + compaction + retry_after + web_search.
Everything else was multi_agent_chat-only (the boundary just passes through).
Move the multi_agent_chat-only cluster into multi_agent_chat/shared/ (files
moved verbatim via git rename; ~116 import sites rewritten):
errors, feature_flags, filesystem_selection, path_resolver, prompt_caching,
sandbox, llm_config, mention_resolver
middleware/busy_mutex, middleware/kb_persistence
busy_mutex/llm_config/mention_resolver are boundary-only but import the moved
modules, so they were folded in to avoid a backwards shared -> multi_agent_chat
dependency. main_agent builders now import the impls directly; the shared
middleware barrel keeps only the genuinely-shared compaction + retry_after.
Also delete the dead leftover shared/plugins and shared/skills dirs (live
copies already live under main_agent/).
Remaining in app/agents/shared/: context, system_prompt(+prompts), checkpointer,
middleware/{compaction,retry_after,dedup_tool_calls}, tools/. checkpointer and
system_prompt are boundary-only infra pending a dedicated home decision.
Promote the agent feature-flag resolver (AgentFeatureFlags / get_flags) out of
`new_chat` into the cross-agent `app/agents/shared` kernel.
feature_flags is a pure leaf consumed across the multi-agent middleware stack,
the chat routes, and tests. Moved it via git mv (content unchanged) and flipped
all 37 importers to app.agents.shared.feature_flags. A thin re-export shim
remains at new_chat/feature_flags.py only for the not-yet-retired single-agent
(chat_deepagent); it goes away with the single-agent deletion.
Behavior-preserving: only import paths change. 1243 tests green.
