fix(conversations): resume Droid provider sessions

[janburzinski]

summary

finally droid actually resumes the last conversation

[greptile-apps]

Greptile Summary

This PR wires up end-to-end Droid provider session resumption: a new SessionStart hook captures the provider-native UUID from Droid, persists it in the conversation's JSON config column, and the resume path now passes that UUID (rather than the Emdash conversation ID) to droid --resume.

• Session capture: A new SessionStart hook entry in the Droid config posts to the hook server; handleProviderSessionHook extracts the session UUID and saveProviderSessionId writes it to the DB, emitting a conversationChanged event for live UI updates.
• Resume logic: resolveAgentSessionCommandArgs selects providerSessionId for local Droid resumes and falls back to starting a fresh session when no UUID has been stored yet; SSH conversations use requireProviderSessionId: false to preserve the existing passthrough behaviour.
• Config refactor: createConversation and mapConversationRowToConversation migrate from ad-hoc JSON.parse/stringify to the new conversation-config helpers, and providerSessionId is surfaced on the Conversation type.

Confidence Score: 5/5

Safe to merge; changes are well-scoped and the fallback paths preserve existing behaviour when no provider session ID has been captured yet.

The session-capture and resume paths are logically correct, backed by new unit tests for every branch, and the config refactor is a straightforward extraction with no behavioural change. The only gap is a silent early-return in handleProviderSessionHook when none of the three candidate field names match Droid's actual response body, which would cause the feature to stop working without any diagnostic signal.

src/main/core/agent-hooks/handle-provider-session-hook.ts — the field-name lookup has no warn log on the 'no matching field' path, which would make a future Droid API change very hard to diagnose.

Important Files Changed

Filename	Overview
src/main/core/agent-hooks/handle-provider-session-hook.ts	New handler that extracts Droid's session UUID from the SessionStart hook body and persists it; guards against non-droid providers and invalid JSON but silently exits when no matching field name is found.
src/main/core/conversations/save-provider-session-id.ts	New module that persists the Droid session UUID into the JSON config column and emits a conversationChanged event; correctly validates UUID format and short-circuits on no-op updates.
src/main/core/conversations/resolve-agent-session-command.ts	New helper that selects the correct sessionId/isResuming pair for Droid (provider UUID vs conv ID) and passes through unchanged for all other providers.
src/shared/conversation-config.ts	New module centralising conversation config serialization/parsing; well-typed with explicit field extraction and UUID validation for Droid session IDs.
src/shared/agent-provider-registry.ts	Adds resumeFlag '--resume' to the Droid provider; sets sessionIdFlag to '--resume' as a sentinel (value unused, presence enables session-ID-as-argument logic) — documented via an inline comment.
src/main/core/conversations/impl/local-conversation.ts	Delegates session ID resolution to the new resolveAgentSessionCommandArgs helper before building the agent command.
src/main/core/conversations/impl/ssh-conversation.ts	Same delegation to resolveAgentSessionCommandArgs as local-conversation, but with requireProviderSessionId: false to preserve the existing resume-passthrough behaviour over SSH.
src/main/core/agent-hooks/agent-hook-service.ts	Routes 'session'-type hook events to the new handleProviderSessionHook before the generic enrichEvent/emit path.
src/main/core/conversations/utils.ts	Switches from raw JSON.parse to parseConversationConfig and surfaces providerSessionId on the mapped Conversation object.

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

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### Issue 1 of 1
src/main/core/agent-hooks/handle-provider-session-hook.ts:22-24
**Silent failure when no matching session ID field is found**

If Droid's `SessionStart` hook body uses a field name that doesn't match any of `session_id`, `provider_session_id`, or `providerSessionId`, the function returns without logging anything. The entire "resume Droid sessions" feature would then silently not work — there'd be no `providerSessionId` stored, and every resume attempt would fall back to starting fresh. A `log.warn` on the early-return path would make this much easier to diagnose.

_{Reviews (2): Last reviewed commit: "fix(conversations): clarify Droid resume..." | Re-trigger Greptile}

[janburzinski]

@greptileai