chore(changelog): restore #6296 núcleo bullet eaten by release-merge auto-resolve

Sync com release/v3.8.45 (irmão #6296 do par #6246 mergeado). O auto-resolve do
CHANGELOG substituiu o bullet-núcleo pelo do #6299; ambos os bullets do #6246
(núcleo #6296 + delta Test-All #6299) devem coexistir. Net-aditivo (+2, -0).

CHANGELOG.md

@@ -15,6 +15,8 @@
 
 ### 🐛 Bug Fixes
 
+- **fix(proxy):** stop the v3.8.44 proxy regression that leaked the real IP and disabled healthy proxies ([#6246](https://github.com/diegosouzapw/OmniRoute/issues/6246)). Two coupled defects from the new health scheduler: (1) **IP leak** — when a proxy assigned to a connection was marked `inactive`, resolution fell through to a **direct** egress instead of blocking, exposing the operator's real IP; (2) **over-deactivation** — the sweep flipped a proxy to `inactive` on the **first** failed probe and counted our own 5s timeout / a probe-target `5xx` as the proxy's fault, so healthy paid proxies vanished from egress selection ("my proxies are not being used anymore"). Fix: the sweep decision is extracted into a pure, network-free `decideProxyHealthAction` (`src/lib/proxyHealth/decision.ts`) — by default the health check now **only counts/logs and never downgrades status** (a proxy is downgraded/removed only with `PROXY_AUTO_REMOVE=true`, after `PROXY_AUTO_REMOVE_AFTER` **consecutive** conclusive failures); probes are classified tri-state so an inconclusive result (our timeout, or a `5xx` from the probe target) never penalizes the proxy, and the probe timeout is raised 5s→15s. Separately, `safeResolveProxy` now **fails closed** via the existing policy: a connection whose assigned proxy is dead is blocked instead of leaking direct (`hasBlockingProxyAssignment`), honoring the explicit `proxy off` toggles and the `PROXY_FAIL_OPEN=true` opt-out. Existing proxies stuck `inactive` by the old behavior need a one-time manual re-activate (the operator owns proxy status). Regression guards: `tests/unit/proxy-health-decide-action-6246.test.ts`, `tests/unit/proxy-assigned-unavailable-6246.test.ts`.
+
 - **fix(proxy):** make "Test All" read-only and add bulk enable/disable ([#6246](https://github.com/diegosouzapw/OmniRoute/issues/6246)). Complements the core fail-closed / scheduler fix (#6296) with the two remaining reporter asks. (1) The **"Test All" button** (`POST /api/settings/proxies/auto-test`) used to flip a proxy to `inactive` on a failed reachability probe; since the egress selector excludes `inactive` proxies, a flaky probe (an unreachable `httpbin.org`, a proxy that blocks `HEAD`, or a slow paid proxy) silently disabled every proxy that failed — "Test All" is now **read-only by default** (only the operator sets a proxy active/inactive; opt back into the legacy test-and-set with `PROXY_HEALTH_AUTO_DEACTIVATE=true`). (2) Adds a **bulk enable/disable** proxies endpoint + toolbar action (`POST /api/settings/proxies/batch-activate`) so an operator can re-activate proxies in one click. Regression guard: `tests/unit/proxy-health-6246.test.ts`. (thanks @tenshiak)
 
 - **chatcore (tools): stop the default 128-tool cap from silently dropping opencode's `task`/MCP tools.** opencode (used as an MCP/agent host) sends a large tool list; when it exceeds the speculative `MAX_TOOLS_LIMIT` (128) default, `truncateToolList` did a blind `tools.slice(0, 128)`, dropping every tool past index 128 — including opencode's built-in `task` tool (subagent launch) and many MCP tools, so models routed through OmniRoute could no longer spawn subagents or reach part of their tools. The cap exists to avoid upstream `400`s for providers with real hard limits (e.g. grok-cli 200), so it is kept for those: detection of the opencode client (`isOpencodeClient` — any `x-opencode-*` header, or `opencode` in the user-agent) now only bypasses the **speculative 128 default**, never a known provider ceiling. Precedence is explicit — a proactive/detected provider limit always truncates (even for opencode); otherwise opencode forwards its full tool list; otherwise the unchanged 128 default applies to every other client. Refactors `getEffectiveToolLimit` into `getKnownToolLimit(provider) ?? DEFAULT_LIMIT` (byte-identical for existing callers) and fixes a cosmetic debug-log that reported the truncated count instead of the original. Regression guard: `tests/unit/tool-limit-detector.test.ts`.