diff --git a/.gitignore b/.gitignore
index b6c9587..0af2958 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,3 +27,4 @@ dist/
 build/
 *.egg-info/
 public/
+.playwright-cli/
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3488c56..3881f16 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,10 @@ from v0.1.0 onward.
 
 ### Changed
 
+- GitHub Action default `python-version` input changed from `"3.14"`
+  to `"3.12"`, matching the declared `requires-python` floor and
+  saving a cold `setup-python` download for downstream consumers
+  (slice #51).
 - GitHub Action runtime no longer installs the `neo4j` driver; only
   `playwright` and `pyyaml` are pulled, matching the base package surface
   (slice #39).
diff --git a/action.yml b/action.yml
index f6572eb..490e54e 100644
--- a/action.yml
+++ b/action.yml
@@ -28,7 +28,7 @@ inputs:
   python-version:
     description: "Python runtime version used to run RADE CLI."
     required: false
-    default: "3.14"
+    default: "3.12"
   fail-on-regression:
     description: "If true, fail when reusability drops or accessibility risk rises."
     required: false
diff --git a/docs/NEXT_EXECUTION_BACKLOG.md b/docs/NEXT_EXECUTION_BACKLOG.md
index 4c4f041..5afcf85 100644
--- a/docs/NEXT_EXECUTION_BACKLOG.md
+++ b/docs/NEXT_EXECUTION_BACKLOG.md
@@ -212,6 +212,14 @@
 - Acceptance: README links to `CHANGELOG.md`; no other changes
 - Does NOT include: generating release notes automatically, splitting the changelog by version, or restructuring the README
 
+### 51. Conservative default Python for the GitHub Action + gitignore Playwright CLI traces
+
+- Status: implemented 2026-04-19
+- Risk reduced: `action.yml` advertised `python-version` default `"3.14"`, but Python 3.14 is still the newest minor and is not yet universally cached on GitHub-hosted runners — every external consumer using our Action would therefore pay a cold `setup-python` download on every run even though the package fully supports `3.12` (our declared `requires-python` floor). Dropping to `3.12` as the Action default removes that cold-start tax for downstream consumers; maintainers who want newer versions can still opt in via the input. Separately, `.playwright-cli/` trace/console artifacts from local `rade analyze --url` runs were leaking into `git status`, risking accidental commits of browser debugging data.
+- Scope: (a) change `action.yml` default `python-version` from `"3.14"` to `"3.12"`; (b) add `.playwright-cli/` to `.gitignore`. No code or test changes.
+- Acceptance: 211 pytest pass unchanged; `.playwright-cli/` no longer appears in `git status` after a run; Action users who pin `python-version` are unaffected
+- Does NOT include: dropping 3.14 from the matrix (wheel-smoke still tests it), changing `requires-python`, or adding a second Action for a higher floor
+
 ### 49. Drop CodeQL badge from README banner
 
 - Status: implemented 2026-04-19