fix(preset): remove unnecessary mutable reference warning

docs/src/content/docs/configuration/extends.md

@@ -76,10 +76,6 @@ runok distinguishes between mutable and immutable references for caching:
 
 Mutable references (tags, branches) are cached for 24 hours by default. Immutable references (commit SHAs) are cached permanently. See [Environment Variables](/configuration/environment-variables/) for how to configure the cache TTL.
 
-:::caution
-runok warns when you use mutable references (tags, branches, or default branch) because they can change over time. For reproducible builds, prefer pinning to a specific commit SHA.
-:::
-
 ## Resolution Order
 
 When a config file specifies `extends`, runok resolves presets using depth-first traversal:

docs/src/content/docs/troubleshooting/common-issues.md

@@ -93,29 +93,6 @@ Look for the `[verbose] No rules matched` message to confirm, then check the fol
 warning: Failed to update preset 'github:org/repo', using cached version
 ```
 
-## Mutable preset reference warnings
-
-**Symptom:** Warning message about mutable preset references appears on every run.
-
-```
-warning: Mutable preset reference 'github:org/repo@main'
-  Consider pinning to a commit SHA for reproducibility
-```
-
-**Cause:** The `extends` field uses a branch name, tag, or version without pinning to a specific commit. This is risky because the upstream content can change unexpectedly.
-
-**Solution:** Pin to a commit SHA:
-
-```yaml
-# Before
-extends:
-  - 'github:org/repo@main'
-
-# After
-extends:
-  - 'github:org/repo@a1b2c3d4e5f6'
-```
-
 ## Sandbox errors
 
 **Symptom:** Commands fail with sandbox-related error messages.

src/config/preset_remote.rs

@@ -42,11 +42,6 @@ impl GitHubVersion {
         matches!(self, Self::CommitSha(_))
     }
 
-    /// Whether this is a mutable reference that should trigger a warning.
-    pub fn is_mutable(&self) -> bool {
-        !self.is_immutable()
-    }
-
     /// Convert to a git ref string for `--branch` or `checkout`.
     pub fn as_git_ref(&self) -> Option<&str> {
         match self {
@@ -263,23 +258,6 @@ fn resolve_git_params(reference: &PresetReference) -> GitParams {
     }
 }
 
-/// Emit a warning to stderr if the reference is mutable.
-fn emit_mutable_warning(reference: &PresetReference, original: &str) {
-    let is_mutable = match reference {
-        PresetReference::GitHub { version, .. } => version.is_mutable(),
-        PresetReference::GitUrl { git_ref, .. } => {
-            git_ref.as_deref().is_none_or(|r| !is_commit_sha(r))
-        }
-        PresetReference::Local(_) => false,
-    };
-    if is_mutable {
-        eprintln!(
-            "warning: Mutable preset reference '{original}'\n  \
-             Consider pinning to a commit SHA for reproducibility"
-        );
-    }
-}
-
 /// Read a preset config file from a directory.
 ///
 /// When `preset_path` is `None`, reads `runok.yml` (or `runok.yaml`) from the root.
@@ -356,8 +334,6 @@ pub fn load_remote_preset<G: GitClient>(
     git_client: &G,
     cache: &PresetCache,
 ) -> Result<Config, ConfigError> {
-    emit_mutable_warning(reference, original_reference);
-
     let params = resolve_git_params(reference);
     let cache_dir = cache.cache_dir(original_reference);
     let preset_path = preset_path_from_reference(reference);
@@ -653,19 +629,6 @@ mod tests {
         assert_eq!(is_commit_sha(input), expected);
     }
 
-    // === GitHubVersion mutability ===
-
-    #[rstest]
-    #[case::sha_immutable(
-        GitHubVersion::CommitSha("abc1234def567890abc1234def567890abc12345".into()),
-        false
-    )]
-    #[case::tag_mutable(GitHubVersion::Tag("v1.0.0".into()), true)]
-    #[case::latest_mutable(GitHubVersion::Latest, true)]
-    fn version_mutability(#[case] version: GitHubVersion, #[case] expected_mutable: bool) {
-        assert_eq!(version.is_mutable(), expected_mutable);
-    }
-
     // === GitHub shorthand → git URL conversion ===
 
     #[rstest]