docs: refresh README + CURRENT.md for v2.7.17 (Orchestrator)

Bring README current (was v2.2.1): add the Orchestrator, the Files/Git diff
panel, persistent agent sessions + claude Agent-SDK, fix the provider list
(5 — cursor/copilot retired), drop the broken AGENTS.md link, update latest
release + planned. Refresh CURRENT.md to v2.7.17 on main.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CURRENT.md

@@ -1,9 +1,9 @@
 # Current focus
 
-Last updated: 2026-06-02
+Last updated: 2026-06-03
 
-- **Last shipped:** `v2.7.8-ember-coder-tabs-model-chips` (2026-06-01)
-- **Branch:** `codebase-audit-cleanup` (audit + cleanup epic, off main HEAD)
-- **In progress:** Phase 3 — stale comments + docs refresh
+- **Last shipped:** `v2.7.17-orchestrator` (2026-06-03) — in-app multi-agent Orchestrator on local Qwen.
+- **Branch:** `main`
+- **In progress:** nothing committed — dogfooding the Orchestrator to surface the next real backlog. Claude Agent-SDK backend enabled (`CLAUDE_SDK_BACKEND`). Optional/exploratory: verify-gate ensembler over pending changes.
 
 See `CHANGELOG.md` for the full shipped history. That file is always authoritative; this file is a quick orientation pointer only.