Fix group-scoped conversation invite source storage

application/single_app/config.py

@@ -98,7 +98,7 @@
 EXECUTOR_TYPE = 'thread'
 EXECUTOR_MAX_WORKERS = 30
 SESSION_TYPE = 'filesystem'
-VERSION = "0.261.023"
+VERSION = "0.261.024"
 IS_DEVELOPMENT = is_development_env_enabled()
 
 # Opt-out for deployments where App Service Easy Auth is active but the platform

application/single_app/functions_collaboration.py

@@ -1114,10 +1114,23 @@
 
 
 def ensure_group_collaboration_for_legacy_conversation(source_conversation_id, owner_user, invited_participants=None):
-    source_conversation_doc = cosmos_group_conversations_container.read_item(
-        item=source_conversation_id,
-        partition_key=source_conversation_id,
-    )
+    source_container = cosmos_group_conversations_container
+    copy_source_messages = _copy_legacy_group_messages_to_collaboration
+    source_link_field = 'legacy_source_conversation_id'
+    try:
+        source_conversation_doc = source_container.read_item(
+            item=source_conversation_id,
+            partition_key=source_conversation_id,
+        )
+    except CosmosResourceNotFoundError:
+        # Group context can classify a conversation without moving its backing stores.
+        source_container = cosmos_conversations_container
+        copy_source_messages = _copy_legacy_personal_messages_to_collaboration
+        source_link_field = 'source_conversation_id'
+        source_conversation_doc = source_container.read_item(
+            item=source_conversation_id,
+            partition_key=source_conversation_id,
+        )
     owner_summary = owner_user or {}
     owner_user_id = str(owner_summary.get('user_id') or '').strip()
     if not owner_user_id:
@@ -1196,8 +1209,9 @@
     )
     collaboration_conversation_doc['strict'] = bool(source_conversation_doc.get('strict', False))
     collaboration_conversation_doc['summary'] = source_conversation_doc.get('summary')
-    collaboration_conversation_doc['legacy_source_conversation_id'] = source_conversation_id
-    collaboration_conversation_doc['legacy_source_scope'] = 'group'
+    collaboration_conversation_doc[source_link_field] = source_conversation_id
+    if source_link_field == 'legacy_source_conversation_id':
+        collaboration_conversation_doc['legacy_source_scope'] = 'group'
 
     source_context = list(source_conversation_doc.get('context', []) or [])
     if source_context:
@@ -1209,7 +1223,7 @@
     if source_locked_contexts:
         collaboration_conversation_doc['locked_contexts'] = source_locked_contexts
 
-    copied_messages = _copy_legacy_group_messages_to_collaboration(
+    copied_messages = copy_source_messages(
         source_conversation_id,
         collaboration_conversation_doc.get('id'),
         owner_summary,
@@ -1230,7 +1244,9 @@
     source_conversation_doc['converted_to_collaboration_at'] = conversion_timestamp
     source_conversation_doc['is_hidden'] = True
     source_conversation_doc['last_updated'] = conversion_timestamp
-    cosmos_group_conversations_container.upsert_item(source_conversation_doc)
+    source_container.upsert_item(source_conversation_doc)
+    invalidate_conversation_cache_for_item(source_conversation_doc, reason="collaboration_source_converted")
+    invalidate_conversation_cache_for_item(collaboration_conversation_doc, reason="collaboration_converted")
 
     log_event(
         '[COLLABORATION] Converted group conversation into collaborative conversation',

docs/explanation/features/GROUP_COLLABORATION_MEMBER_INVITE_FIX_PLAN.md

@@ -2,9 +2,15 @@
 
 Planning version: **0.250.062**
 
-Implemented in version: **Not implemented - discovery and planning only**
+Historical plan status: **Discovery and planning only; not implemented in full**
 
-Related configuration version: `application/single_app/config.py` currently sets `VERSION = "0.250.062"`.
+Related configuration version at planning time: `application/single_app/config.py` set `VERSION = "0.250.062"`.
+
+The backend source-storage mismatch described below is fixed for Development/v1 in
+**0.261.024** under [#1472](https://github.com/microsoft/simplechat/issues/1472).
+See [Group Collaboration Source Storage Fix](../fixes/GROUP_COLLABORATION_SOURCE_STORAGE_FIX.md)
+for the implemented scope and coverage. This does not implement this historical
+plan's UI wording, stale-DOM, or endpoint-selection proposals.
 
 ## Overview
 
@@ -315,4 +321,3 @@ Cover:
 1. Should `/from-group/<id>/members` delegate when `<id>` is already a group collaborative conversation ID, or should it return a diagnostic error?
 2. Should the UI show a one-line hint with the active group name in the participant picker?
 3. Should group participant suggestions include pending group users, or only accepted/current group members? Current behavior should remain accepted/current members unless product requirements change.
-

docs/explanation/fixes/GROUP_COLLABORATION_SOURCE_STORAGE_FIX.md

@@ -0,0 +1,167 @@
+# Group Collaboration Source Storage Fix (v0.261.024)
+
+Fixed in version: **0.261.024**
+
+Related issue: [#1472](https://github.com/microsoft/simplechat/issues/1472).
+
+The application patch version in `application\single_app\config.py` changes from
+**0.261.023** to **0.261.024** for this Development/v1 fix.
+
+## Issue
+
+Adding the first participant to an existing group-scoped single-user conversation
+could return `404 Conversation not found`, even while its owner could still open
+the conversation and read its history.
+
+V1 sends this invitation to the existing endpoint:
+
+```text
+POST /api/collaboration/conversations/from-group/<conversation_id>/members
+```
+
+The failure occurred during source lookup, before the selected invitee was
+evaluated. It did not necessarily mean the conversation had been deleted.
+
+## Root cause
+
+Normal conversation creation writes to `conversations`, with history in
+`messages`. Group knowledge or a group agent can later establish primary group
+context and classify the same record as `group-single-user` without moving either
+record set.
+
+Group collaboration conversion assumed a different physical layout:
+`group_conversations` and `group_messages`. The lookup, history copier, original
+source update, and collaboration source links all followed that assumption.
+Changing only the lookup would have left the copied history and later source
+operations pointed at the wrong containers.
+
+## Implementation
+
+`ensure_group_collaboration_for_legacy_conversation()` now keeps the source
+conversation container, existing message copier, and source-link field together
+through conversion.
+
+Legacy group storage remains authoritative. Only a
+`CosmosResourceNotFoundError` from that lookup permits a regular-storage lookup.
+Authorization failures, throttling, service failures, and other exceptions do not
+trigger another-store retry. If both containers lack the record, the endpoint
+still returns the existing 404.
+
+| Original layout | History copier | Link on the collaborative conversation |
+| --- | --- | --- |
+| `conversations` / `messages` | `_copy_legacy_personal_messages_to_collaboration()` | `source_conversation_id` |
+| `group_conversations` / `group_messages` | `_copy_legacy_group_messages_to_collaboration()` | `legacy_source_conversation_id`, with `legacy_source_scope = 'group'` |
+
+Both paths create a group collaboration. Reusing the regular-storage copier does
+not change the conversation's group access rules. It preserves the distinction
+between group workspace context and `source_conversation_scope = 'group'` message
+provenance, which specifically selects the legacy group message store.
+
+Conversion preserves the existing title, context, tags, classification,
+citation-tracking fields, strict mode, summary, and scope locks. The existing
+copiers preserve supported message content and metadata, chronological ordering,
+uploaded-content attribution, artifact filtering, and generated-image message
+associations. Message counts and previews continue to derive from the copied
+transcript.
+
+The original is hidden and back-linked in its actual container. Cache
+invalidation runs after the hidden source and completed collaboration have been
+persisted, preventing cached conversation lists from retaining the pre-conversion
+state.
+
+### Source lifecycle
+
+For a regular-stored original, the existing shared AI source helper reuses
+`source_conversation_id` and its history instead of creating an empty backing
+conversation. Repeat invitations still reuse the collaboration after that helper
+updates the backing record's chat type and kind.
+
+Legacy group originals retain their existing separate AI backing-source behavior.
+The existing masking, deletion, archival, and retention helpers use the matching
+source links and message provenance without new storage schemas or migrations.
+Cleanup continues to enforce its source ownership and backward-link guards.
+
+### Preserved restrictions and API contract
+
+- Only the source conversation owner can convert an eligible group conversation.
+- The owner must still hold a current allowed group role, and the group's status
+  must allow chat. Existing chat permissions for active, locked, and
+  upload-disabled groups remain unchanged; inactive groups remain rejected.
+- Invitees must already be current group members. This flow does not add people
+  to a group workspace or allow arbitrary directory users into the conversation.
+- Rejected ownership, group, or invitee requests do not copy history or write
+  conversion state.
+- New conversions return 201 with `created: true`; subsequent invitations reuse
+  the collaboration and return 200 with `created: false`. Response fields and
+  creation/invitation events are unchanged.
+
+## Files changed
+
+- `application\single_app\functions_collaboration.py`: paired source selection,
+  existing copier/link selection, original-container update, and final cache
+  invalidation.
+- `application\single_app\config.py`: application patch version.
+- `functional_tests\test_group_collaboration_source_storage_fix.py`: isolated
+  behavioral regressions using actual production helpers and the v1 route.
+- `docs\explanation\features\GROUP_COLLABORATION_MEMBER_INVITE_FIX_PLAN.md`:
+  distinguish this implemented backend fix from the historical UI proposals.
+
+The route module, personal conversion implementation, and downstream cleanup
+helpers are unchanged.
+
+## Validation
+
+The new regression first reproduced the exact 404 through the actual v1
+conversion handler against a regular-stored group conversation before the
+production fix.
+
+Run the focused behavioral coverage with:
+
+```powershell
+python -m pytest -q .\functional_tests\test_group_collaboration_source_storage_fix.py
+```
+
+The regression executes the production conversion, participant normalization,
+group role/status checks, source bridge, metadata synchronization, masking, and
+cleanup helpers against partition-aware in-memory stores. Flask request-context
+dispatch exercises the existing route without application startup, Azure clients,
+or deployed services.
+
+Coverage includes both layouts, all existing allowed group roles and chat
+statuses, empty and populated histories, repeated invitations, current membership
+revalidation, personal conversion compatibility, lookup priority, no-mutation
+rejections, service-error responses, and manual/retention/archive cleanup that
+leaves unrelated records untouched.
+
+The new regression passes **18 tests and 106 subtests** under pytest. The combined
+conversion, participant, image-proposal, shared-AI, retention, route-policy, and
+documentation run completed with **60 tests and 106 subtests passing**, plus the
+one pre-existing uploaded-image regression failure described below.
+
+| Scenario | Before | After |
+| --- | --- | --- |
+| First group invitation for a regular-stored source | 404 before copying history | 201, with preserved transcript and a linked, hidden regular source |
+| Legacy group-store conversion | Supported | Remains supported with its existing source conventions |
+| Another invitation after conversion | Reuse required | 200, same collaboration, no transcript copy |
+| Missing source in both stores | 404 | Same 404 |
+| Non-not-found source storage error | Must surface as an error | No cross-store fallback or false success |
+
+One related pre-existing regression,
+`test_collaboration_legacy_message_conversion.py::test_uploaded_image_conversion_preserves_user_sender`,
+already fails on the Development baseline: it expects the older uploaded-image
+role/content representation rather than the model's current image representation.
+That model and test are unchanged. The new conversion coverage checks preservation
+of the current uploaded-image sender metadata, provenance, and associations.
+
+## Scope and impact
+
+Owners can share affected group-scoped conversations without moving stored data
+or losing the original history. Existing group authorization and participant
+restrictions remain in place.
+
+This change is limited to the Development/v1 backend, regression coverage, and
+documentation. It makes no React/v2 implementation or parity claim and includes no
+UI wording changes, new routes/settings, deployment changes, or data migration.
+The broader proposals in the
+[historical group invitation plan](../features/GROUP_COLLABORATION_MEMBER_INVITE_FIX_PLAN.md)
+are not represented as completed by this fix.