Document published evidence context

docs/config.md

@@ -211,19 +211,41 @@ Validator bindings accept only **module**, **llm_profile**, and **options**.
 They reject **references**, **retries**, and nested **validators**. Deterministic
 validators reject an explicit **llm_profile**.
 
-The **json** output module accepts one option:
+The **json** output module accepts optional **include_chunk_map** and
+**evidence_context** settings:
 
 ~~~yaml
 output:
   module: json
   options:
     include_chunk_map: true
+    evidence_context:
+      enabled: true
+      window_units: 3
+      lanes:
+        - npcs
+        - spells
 ~~~
 
 **include_chunk_map** is a boolean and defaults to false. It adds the accepted
 chunk map when one exists; its wire format is defined in the
 [chunk-map contract](integrations/chunk-map.md).
 
+Omitting **evidence_context** disables evidence publication. When present, it
+is an object with these strict fields:
+
+| Field | Type | Rules |
+| --- | --- | --- |
+| **enabled** | boolean | Required. `false` permits no other evidence fields. |
+| **lanes** | array of strings | Required and non-empty when enabled. Each value is trimmed and must be unique; every value must name a configured pipeline lane. |
+| **window_units** | non-negative integer | Optional when enabled; defaults to 3. Zero retains only directly cited units. |
+
+Unknown outer or nested option fields are rejected, as are incompatible YAML
+types. The allowlist remains valid when a run uses lane filtering: a configured
+lane that is not active for that invocation simply contributes no evidence.
+Evidence publication is opt-in because it can persist source text and metadata.
+Its payload contract is [Published Evidence Context](integrations/evidence-context.md).
+
 ## References And Ordered Handoffs
 
 Reference maps bind named slots that the selected target declares. A scalar is