docs: fix dead links in the PR template and backends docs (#11884)

- the PR template's 'Signed commits' anchor pointed at a CONTRIBUTING
  section that does not exist; repointed at the Commit messages
  section
- the longcat-video backend README linked a docs page that was never
  committed; replaced the dead link with plain text
- formal-verification/README.md used ../../../ for five in-repo
  packages (escaping the repo root); fixed to ../

.github/PULL_REQUEST_TEMPLATE.md

@@ -5,7 +5,7 @@ This PR fixes #
 **Notes for Reviewers**
 
 
-**[Signed commits](../CONTRIBUTING.md#signing-off-on-commits-developer-certificate-of-origin)**
+**[Signed commits](../CONTRIBUTING.md#commit-messages)**
 - [ ] Yes, I signed my commits.
 - [ ] Documentation updated (docs/content/) for user-facing changes, or not applicable
  

backend/python/longcat-video/README.md

@@ -11,7 +11,7 @@ RPC. It supports:
   systems such as NVIDIA DGX Spark.
 
 Install the `longcat-video` or `longcat-video-avatar-1.5` recipe from the
-LocalAI Model Gallery. See the [LongCat user guide](../../../docs/content/features/longcat-video.md)
+LocalAI Model Gallery. LongCat video backend
 for Studio and API examples, hardware requirements, and manual configuration.
 
 The upstream source is pinned in `Makefile` and patched at build time. The

formal-verification/README.md

@@ -24,11 +24,11 @@ then the implementation is checked against them.
 | `fizzbee.sha256` | Pinned checksum(s) of the FizzBee release the gate uses (created on first `install-fizzbee.sh` run). |
 
 The implementations under test live in
-[`core/http/endpoints/openai/respcoord`](../../../core/http/endpoints/openai/respcoord) (M3),
-[`core/http/endpoints/openai/turncoord`](../../../core/http/endpoints/openai/turncoord) (M2),
-[`core/http/endpoints/openai/conncoord`](../../../core/http/endpoints/openai/conncoord) (M1),
-[`core/http/endpoints/openai/compactcoord`](../../../core/http/endpoints/openai/compactcoord) (M4),
-and [`core/http/endpoints/openai/ttscoord`](../../../core/http/endpoints/openai/ttscoord) (M5).
+[`core/http/endpoints/openai/respcoord`](../core/http/endpoints/openai/respcoord) (M3),
+[`core/http/endpoints/openai/turncoord`](../core/http/endpoints/openai/turncoord) (M2),
+[`core/http/endpoints/openai/conncoord`](../core/http/endpoints/openai/conncoord) (M1),
+[`core/http/endpoints/openai/compactcoord`](../core/http/endpoints/openai/compactcoord) (M4),
+and [`core/http/endpoints/openai/ttscoord`](../core/http/endpoints/openai/ttscoord) (M5).
 
 ## Running the realtime gate