fix(gateway): honor per-platform session isolation overrides

[Diaspar4u]

Summary

• honor per-platform group_sessions_per_user and thread_sessions_per_user session-key overrides
• preserve nested <platform>.extra values while loading config
• keep authorization, persisted /resume scoping, Discord prospective-thread attribution, and sender attribution aligned with the same effective per-platform isolation policy

Test plan

• scripts/run_tests.sh tests/gateway/test_session.py tests/gateway/test_resume_command.py tests/gateway/test_config.py tests/gateway/test_whatsapp_text_batching.py tests/gateway/test_whatsapp_group_gating.py -q
• ruff check gateway/config.py gateway/run.py gateway/session.py gateway/slash_commands.py tests/gateway/test_config.py tests/gateway/test_session.py tests/gateway/test_resume_command.py
• git diff --check

Supersedes #81207, including its reported prompt-context gap. The first two session-isolation commits were carried from the stack in #81208 with original authorship preserved; #81208 retains separate WhatsApp mention-tagging scope.

[Diaspar4u]

Re-review requested. Closed the remaining per-platform isolation gaps in authorization, persisted /resume scoping, Discord prospective-thread attribution, and config loading while keeping the PR focused on session isolation overrides.

Validation: 152 focused gateway tests passed; focused Ruff, diff checks, and SSH signature verification passed.

[Diaspar4u]

Rebased the completed isolation fix onto current main at head d8b6490fd6; the only overlapping upstream change in gateway/run.py was preserved. All four upstream-range commits have verified SSH signatures.

Validation: 164 focused gateway tests passed; focused Ruff, git diff --check, and upstream-range diff checks passed.

GitHub Actions for exact head d8b6490fd67e22af9265aaabad5274c24dffc388 are awaiting write-access approval; please approve the CI and Docker workflow runs.

@coderabbitai review

Maintainers: please re-review the current head.

[Diaspar4u]

@teknium1 @alt-glitch please re-review the current head.

[Enough1122]

AI code review — automated review for reference, author can ignore or act on any point.

fix(gateway): honor per-platform session isolation overrides

Centralizing resolution in resolve_session_isolation() and threading it through the key/attribution/auth paths is the right approach, and the override tests are good. Observations:

1. Duplicated resolution in build_session_context. gateway/session.py build_session_context re-implements the platform-extra lookup inline (platform_extra.get(...)) instead of calling resolve_session_isolation(config, source) — two implementations that can drift. Consider having it call the helper.
2. is_shared_multi_user_session semantic change via effective_session_thread_id. Switching from source.thread_id to thread_id or prospective_thread_id changes shared/isolated classification for all platforms with prospective threads, not just the ones under test — a prospective thread now keys off thread_sessions_per_user instead of group_sessions_per_user. The tests document the intent, but confirm this flip is wanted platform-wide, since it also drives /resume scoping and the session-context prompt, not just keying.
3. Overlap with feat(whatsapp): observe authorized group context before response #84926. The session-isolation hunks here (config extra preservation, resolve_session_isolation, effective_session_*) also appear in feat(whatsapp): observe authorized group context before response #84926 — whichever merges second will conflict/duplicate. Coordinate so only one copy lands.

[Diaspar4u]

Addressed all three points on current head c141281d68da:

1. Fixed the duplicated resolution path. build_session_context() now calls the same resolve_session_isolation() helper used by keying, authorization, and attribution.
2. Bound the prospective-thread behavior to its actual contract. Only Discord can promote prospective_thread_id into thread routing/classification; a new regression proves stray prospective metadata on another platform preserves its existing group key and per-user isolation. The existing Discord initiate-in-channel/continue-in-thread behavior and sender attribution remain covered and passing.
3. Confirmed the stack coordination. feat(whatsapp): observe authorized group context before response #84926 is explicitly documented as stacked on this PR and will be refreshed onto main after fix(gateway): honor per-platform session isolation overrides #84925 merges, so the shared isolation commits land only once.

Validation: 165 existing and new session/resume/config/WhatsApp isolation tests passed; focused Ruff, attribution audit, both diff checks, and all six upstream-range SSH signature checks passed.

@teknium1 @alt-glitch please re-review the materially changed current head.

[Diaspar4u]

Fixed profile-safe recovery when a per-user session key becomes shared: durable session ownership now wins over the legacy key namespace, while rows owned by another profile remain rejected. Added continuity and cross-profile rejection regressions.

Current head e9dde73 preserves the validated patch exactly. Validation: 165 focused tests passed; focused Ruff, diff checks, attribution audit, and all upstream-range commit signatures passed.

@teknium1 @alt-glitch please re-review the current head. Actions on this exact SHA are awaiting write-access approval; please approve the workflow runs.

[Diaspar4u]

Final disposition on #81207: #84925 is the preferred replacement. It carries #81207’s two session-isolation commits with original authorship preserved, then applies the same effective per-platform policy consistently to authorization, durable /resume scoping, Discord prospective-thread attribution, shared-session sender attribution, canonical context construction, and nested platform configuration loading. Those additional boundaries prevent session keying from disagreeing with access, replay, or attribution behavior. No unique isolation-fix scope remains in #81207. #81208 remains separate only for its WhatsApp mention-tagging behavior.

[Diaspar4u]

Significant-overlap disposition: #62370 fixes one remaining global group/thread-precedence case inside is_shared_multi_user_session; #84925 instead resolves effective per-platform overrides and applies that policy consistently across keying, authorization, /resume, context construction, and Discord attribution. #62370 is a complementary narrow helper correction, not a replacement for #84925’s broader consistency contract. #47794 is also complementary: it preserves each appended author inside WhatsApp’s debounce batch, while #84925 governs isolation and attribution after the event reaches gateway session handling. Consolidation must retain those two narrow fixes, but neither makes #84925 unnecessary.

[Diaspar4u]

Further relationship disposition: #13939 deliberately decouples sender attribution from session isolation by adding a default-on stable [from … uid:…] prefix in every chat context. #84925 keeps the existing attribution model but makes isolation, authorization, resume visibility, and shared-session attribution agree on the same effective per-platform policy. #13939 is a broader competing attribution contract, not a replacement for #84925’s isolation fix. #75770 is a behavior-preserving extraction of resume authorization from slash_commands.py; if it lands first, #84925’s changed authorization logic must be ported into the new mixin. That structural refactor does not remove #84925’s semantic requirement.

[Enough1122]

AI code review — automated review for reference — not a maintainer.

Thanks for the disposition — noted that #13939 is a broader competing attribution contract rather than a replacement for #84925's isolation fix, and that #75770 only requires porting the authorization logic if it lands first.