Restore test-used save/load methods; remove file_name(), write_run_status, Conclusion::load, save_json

The prior commit over-removed methods still needed by tests. This restores
save/load/from_context on CheckpointExt, ConclusionExt, RunRecordExt, and
RunStatusRecordExt with inlined serialization (no longer using save_json).

Removed: file_name() from RunRecordExt and StartRecordExt (zero callers),
Conclusion::load (zero callers), write_run_status (zero callers),
save_json helper (replaced by inline serialization).

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

lib/crates/fabro-workflow/src/records/checkpoint.rs

@@ -4,7 +4,7 @@ use std::path::Path;
 pub use fabro_types::checkpoint::Checkpoint;
 
 use crate::context::Context;
-use crate::error::{FailureSignature, Result as CrateResult};
+use crate::error::{FabroError, FailureSignature, Result as CrateResult};
 use crate::outcome::Outcome;
 
 pub trait CheckpointExt {
@@ -22,6 +22,7 @@ pub trait CheckpointExt {
     ) -> Self
     where
         Self: Sized;
+    fn save(&self, path: &Path) -> CrateResult<()>;
     fn load(path: &Path) -> CrateResult<Self>
     where
         Self: Sized;
@@ -54,8 +55,14 @@ impl CheckpointExt for Checkpoint {
         }
     }
 
+    fn save(&self, path: &Path) -> CrateResult<()> {
+        let json = serde_json::to_string_pretty(self)
+            .map_err(|e| FabroError::Checkpoint(format!("checkpoint serialize failed: {e}")))?;
+        std::fs::write(path, json)?;
+        Ok(())
+    }
+
     fn load(path: &Path) -> CrateResult<Self> {
-        tracing::debug!(path = %path.display(), "Loading checkpoint");
         crate::load_json(path, "checkpoint")
     }
 }

lib/crates/fabro-workflow/src/records/conclusion.rs

@@ -1 +1,18 @@
+use std::path::Path;
+
 pub use fabro_types::conclusion::{Conclusion, StageSummary};
+
+use crate::error::{FabroError, Result as CrateResult};
+
+pub trait ConclusionExt {
+    fn save(&self, path: &Path) -> CrateResult<()>;
+}
+
+impl ConclusionExt for Conclusion {
+    fn save(&self, path: &Path) -> CrateResult<()> {
+        let json = serde_json::to_string_pretty(self)
+            .map_err(|e| FabroError::Checkpoint(format!("conclusion serialize failed: {e}")))?;
+        std::fs::write(path, json)?;
+        Ok(())
+    }
+}

lib/crates/fabro-workflow/src/records/mod.rs

@@ -4,6 +4,6 @@ mod run;
 mod start;
 
 pub use checkpoint::{Checkpoint, CheckpointExt};
-pub use conclusion::{Conclusion, StageSummary};
+pub use conclusion::{Conclusion, ConclusionExt, StageSummary};
 pub use run::{RunRecord, RunRecordExt};
 pub use start::{StartRecord, StartRecordExt};

lib/crates/fabro-workflow/src/records/run.rs

@@ -2,14 +2,12 @@ use std::path::Path;
 
 pub use fabro_types::run::RunRecord;
 
-use crate::error::Result as CrateResult;
+use crate::error::{FabroError, Result as CrateResult};
 
 const FILE_NAME: &str = "run.json";
 
 pub trait RunRecordExt {
-    fn file_name() -> &'static str
-    where
-        Self: Sized;
+    fn save(&self, run_dir: &Path) -> CrateResult<()>;
     fn load(run_dir: &Path) -> CrateResult<Self>
     where
         Self: Sized;
@@ -20,8 +18,11 @@ pub trait RunRecordExt {
 }
 
 impl RunRecordExt for RunRecord {
-    fn file_name() -> &'static str {
-        FILE_NAME
+    fn save(&self, run_dir: &Path) -> CrateResult<()> {
+        let json = serde_json::to_string_pretty(self)
+            .map_err(|e| FabroError::Checkpoint(format!("run record serialize failed: {e}")))?;
+        std::fs::write(run_dir.join(FILE_NAME), json)?;
+        Ok(())
     }
 
     fn load(run_dir: &Path) -> CrateResult<Self> {

lib/crates/fabro-workflow/src/records/start.rs

@@ -7,19 +7,12 @@ use crate::error::Result as CrateResult;
 const FILE_NAME: &str = "start.json";
 
 pub trait StartRecordExt {
-    fn file_name() -> &'static str
-    where
-        Self: Sized;
     fn load(run_dir: &Path) -> CrateResult<Self>
     where
         Self: Sized;
 }
 
 impl StartRecordExt for StartRecord {
-    fn file_name() -> &'static str {
-        FILE_NAME
-    }
-
     fn load(run_dir: &Path) -> CrateResult<Self> {
         crate::load_json(&run_dir.join(FILE_NAME), "start record")
     }

lib/crates/fabro-workflow/src/run_status.rs

@@ -5,12 +5,18 @@ pub use fabro_types::status::{
 };
 
 pub trait RunStatusRecordExt {
+    fn save(&self, path: &Path) -> std::io::Result<()>;
     fn load(path: &Path) -> std::io::Result<Self>
     where
         Self: Sized;
 }
 
 impl RunStatusRecordExt for RunStatusRecord {
+    fn save(&self, path: &Path) -> std::io::Result<()> {
+        let json = serde_json::to_string_pretty(self).map_err(std::io::Error::other)?;
+        std::fs::write(path, json)
+    }
+
     fn load(path: &Path) -> std::io::Result<Self> {
         let data = std::fs::read_to_string(path)?;
         serde_json::from_str(&data)