Secrets: reject exec SecretRef traversal ids across schema/runtime/gateway (#42370)

* Secrets: harden exec SecretRef validation and reload LKG coverage

* Tests: harden exec fast-exit stdin regression case

* Tests: align lifecycle daemon test formatting with oxfmt 0.36

docs/gateway/configuration-reference.md

@@ -2713,6 +2713,7 @@ Validation:
 - `source: "env"` id pattern: `^[A-Z][A-Z0-9_]{0,127}$`
 - `source: "file"` id: absolute JSON pointer (for example `"/providers/openai/apiKey"`)
 - `source: "exec"` id pattern: `^[A-Za-z0-9][A-Za-z0-9._:/-]{0,255}$`
+- `source: "exec"` ids must not contain `.` or `..` slash-delimited path segments (for example `a/../b` is rejected)
 
 ### Supported credential surface
 

docs/gateway/secrets.md

@@ -114,6 +114,7 @@ Validation:
 
 - `provider` must match `^[a-z][a-z0-9_-]{0,63}$`
 - `id` must match `^[A-Za-z0-9][A-Za-z0-9._:/-]{0,255}$`
+- `id` must not contain `.` or `..` as slash-delimited path segments (for example `a/../b` is rejected)
 
 ## Provider config
 

docs/help/testing.md

@@ -409,3 +409,6 @@ When you fix a provider/model issue discovered in live:
 - Prefer targeting the smallest layer that catches the bug:
   - provider request conversion/replay bug → direct models test
   - gateway session/history/tool pipeline bug → gateway live smoke or CI-safe gateway mock test
+- SecretRef traversal guardrail:
+  - `src/secrets/exec-secret-ref-id-parity.test.ts` derives one sampled target per SecretRef class from registry metadata (`listSecretTargetRegistryEntries()`), then asserts traversal-segment exec ids are rejected.
+  - If you add a new `includeInPlan` SecretRef target family in `src/secrets/target-registry-data.ts`, update `classifyTargetClass` in that test. The test intentionally fails on unclassified target ids so new classes cannot be skipped silently.