fix: validate_story_dirs reads filesystem shadows instead of global CRDT singleton (bug 525)

The post-520 migration changed validate_story_dirs to read from
pipeline_state::read_all_typed() (the process-global CRDT singleton),
ignoring its root: &Path argument. This broke test isolation — tests
creating a tempdir saw dozens of results from ambient CRDT state,
causing non-deterministic failures that blocked every mergemaster gate.

Remove the CRDT singleton block and rely on the filesystem shadow scan
that already uses the root argument correctly. 1845/1845 tests pass.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/src/http/workflow/mod.rs

@@ -344,47 +344,10 @@ pub fn validate_story_dirs(
 ) -> Result<Vec<StoryValidationResult>, String> {
     let mut results = Vec::new();
 
-    // Validate from typed projection + content store.
+    // Validate from filesystem shadows under the given root.
-    {
+    // NOTE: We intentionally read the filesystem here (not the global CRDT
-        let typed_items = crate::pipeline_state::read_all_typed();
+    // singleton) so that tests can pass an isolated tempdir and get
-        for item in typed_items {
+    // deterministic results.  See bug 525.
-            use crate::pipeline_state::Stage;
-            if !matches!(item.stage, Stage::Backlog | Stage::Coding) {
-                continue;
-            }
-            let sid = item.story_id.0.clone();
-            if let Some(content) = crate::db::read_content(&sid) {
-                match parse_front_matter(&content) {
-                    Ok(meta) => {
-                        let mut errors = Vec::new();
-                        if meta.name.is_none() {
-                            errors.push("Missing 'name' field".to_string());
-                        }
-                        if errors.is_empty() {
-                            results.push(StoryValidationResult {
-                                story_id: sid,
-                                valid: true,
-                                error: None,
-                            });
-                        } else {
-                            results.push(StoryValidationResult {
-                                story_id: sid,
-                                valid: false,
-                                error: Some(errors.join("; ")),
-                            });
-                        }
-                    }
-                    Err(e) => results.push(StoryValidationResult {
-                        story_id: sid,
-                        valid: false,
-                        error: Some(e.to_string()),
-                    }),
-                }
-            }
-        }
-    }
-
-    // Filesystem fallback: also check work/ directories.
     let dirs_to_validate = vec![
         root.join(".huskies").join("work").join("2_current"),
         root.join(".huskies").join("work").join("1_backlog"),
@@ -409,11 +372,6 @@ pub fn validate_story_dirs(
                 .unwrap_or_default()
                 .to_string();
 
-            // Skip if already validated from CRDT.
-            if results.iter().any(|r| r.story_id == story_id) {
-                continue;
-            }
-
             let contents = std::fs::read_to_string(&path)
                 .map_err(|e| format!("Failed to read {}: {e}", path.display()))?;
             match parse_front_matter(&contents) {