feat(qa): remote NIM provider + headless-QA robustness

Enable autonomous QA through a remote OpenAI-compatible provider (NVIDIA NIM)
and harden the tool/approval path so unattended multi-stage runs complete.

- inference: add openai_compat provider (Bearer chat-completions for NIM/OpenAI),
  dispatched by provider type "nim"/"openai"; key via api_key/api_key_env.
- server: bind configured [server] host/port instead of a hardcoded 8080;
  POST /sessions accepts an optional `intent` (WS parity) for intent-driven workflows.
- kernel: thread the bound operator profile's approval_mode into per-tool gating so
  auto/yolo enable unattended approval (engine still consulted; policy/plane-2 BLOCK
  stays terminal); on a recoverable tool failure feed the tool's arg-schema back into
  context so the model self-corrects instead of repeating a malformed call.
- tools: split deletion out of file_write into a separate, explicitly-named file_delete
  tool — a model can no longer delete a file by getting a write-mode parameter wrong.
- server: add GET /metrics/tool-reliability — per-model tool-call validity from the
  event log (measurement groundwork for capability-aware routing).
- docs: update AGENTS.md across kernel, tools, server, inference.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

infrastructure/tools/src/main/kotlin/com/correx/infrastructure/tools/ToolConfig.kt

@@ -1,6 +1,7 @@
 package com.correx.infrastructure.tools
 
 import com.correx.core.tools.contract.Tool
+import com.correx.infrastructure.tools.filesystem.FileDeleteTool
 import com.correx.infrastructure.tools.filesystem.FileEditTool
 import com.correx.infrastructure.tools.filesystem.FileReadTool
 import com.correx.infrastructure.tools.filesystem.FileWriteTool
@@ -81,6 +82,14 @@ fun ToolConfig.buildTools(): List<Tool> = buildList {
                 workingDir = fileWrite.workingDir,
             ),
         )
+        // file_delete is the explicit, separately-named deletion capability split out of
+        // file_write; it shares the writer's path jail and is gated by the same fileWrite toggle.
+        add(
+            FileDeleteTool(
+                allowedPaths = fileWrite.allowedPaths,
+                workingDir = fileWrite.workingDir,
+            ),
+        )
     }
     if (fileEdit.enabled) {
         add(

infrastructure/tools/src/test/kotlin/com/correx/infrastructure/tools/SandboxedToolExecutorFileMutationTest.kt

@@ -65,7 +65,7 @@ class SandboxedToolExecutorFileMutationTest {
 
     private fun writeRequest(path: String, content: String) = ToolRequest(
         ToolInvocationId("inv"), SessionId("s"), StageId("st"), "file_write",
-        mapOf("operation" to "write", "path" to path, "content" to content),
+        mapOf("path" to path, "content" to content),
     )
 
     private fun executor(tool: FileWriteTool, store: FakeArtifactStore, events: CapturingEventStore) =