Release DG — stage-batch17 — 9-PR small-fix batch (v0.51.135)

[nesquena-hermes]

Release DG / v0.51.135 — stage-batch17 (9 PRs)

Batched release of 9 small, scope-disjoint contributor fixes. All PRs were CI-green individually, all behavioral changes reuse existing helpers, all CHANGELOG entries present.

PRs merged

PR	Author	Net LOC	Surface
#2917	franksong2702	+162	tests — pin profile= kwarg threading through metadata-only session reads
#2922	ai-ag2026	+172	docs — canonical session resolution RFC
#2912	ai-ag2026	+24/-1	1-line URL parser: ?session_id=<id> alias for ?session=<id>
#2906	ai-ag2026	+7	1-line dedupe in pending-message merge
#2936	franksong2702	+10/-5	gateway/status: identity-map heuristic when alive=None
#2940	george-andraws	+22/-1	chat upload: send absolute server-side path for image attachments
#2927	Carry00	+123/-1	agent_health: profile-scoped gateway.pid fallback
#2921	franksong2702	+54/-3	sessions sidebar: optimistic repaint on Archive/Delete
#2919	franksong2702	+106	clarify card: reserve transcript bottom padding

Verification

• ✅ Pre-merge: all 9 CI-green, no stale-base traps, identical master..PR and merge-base..PR deltas
• ✅ Post-merge: no merge markers, ast.parse clean on all .py, node -c clean on changed JS
• ✅ pytest: 6565 passed / 6 skipped / 3 xpassed / 0 failures (177.75s sequential, -p no:xdist)
• ✅ Opus advisor: SHIP-AS-IS (verified all 6 listed concerns line-by-line: architectural overlap, resize-listener leak, dedupe aggressiveness, URL precedence, profile-fallback exception handling, configured semantics)
• ✅ CHANGELOG [Unreleased] → [v0.51.135] stamped, 6 visible Fixed entries + 1 Added entry

CHANGELOG body

## [v0.51.135] — 2026-05-25 — Release DG (stage-batch17 — 9-PR small-fix batch)

### Added
- Added a proposed canonical session resolution RFC covering URL routes, query parameters, localStorage, sidebar rows, and compression-lineage IDs so future session-routing fixes have one review contract.

### Fixed
- Browser session links that use the API-style `?session_id=<id>` query parameter now open the requested conversation instead of falling back to the last locally stored session.
- Gateway status now treats existing messaging-session metadata as configured when `gateway.status` is unavailable, avoiding a misleading "Gateway not configured" warning for multi-container deployments with active gateway sessions.
- Session sidebar Archive/Delete menu actions now repaint from local sidebar state immediately after the server confirms the mutation, instead of waiting for the full `/api/sessions` refresh before the row disappears.
- Clarification dialogs now reserve transcript space while open or collapsed, so the question prompt no longer covers the assistant text needed to answer it.
- Chat uploads now send the absolute server-side path for image attachments in the agent text context, restoring immediate tool access (e.g. `vision_analyze`) to files uploaded in the current turn.
- Pending uploaded-file user turns no longer double-render when both the optimistic bubble and the server's pending-message hydration produce the same `[Attached files: ...]` suffix.

Notes for reviewers

This is a small-fix batch — every PR is 1–5 LOC behavioral or a focused test/doc add. No new contracts, no architecture changes, no DB migrations. v0.51.134 from earlier today is unchanged; this batch sits cleanly on top.