feat: add git working tree diff toggle in diff panel

apps/server/src/git/Layers/GitCore.ts

@@ -45,6 +45,7 @@ const PREPARED_COMMIT_PATCH_MAX_OUTPUT_BYTES = 49_000;
 const RANGE_COMMIT_SUMMARY_MAX_OUTPUT_BYTES = 19_000;
 const RANGE_DIFF_SUMMARY_MAX_OUTPUT_BYTES = 19_000;
 const RANGE_DIFF_PATCH_MAX_OUTPUT_BYTES = 59_000;
+const WORKING_TREE_DIFF_MAX_OUTPUT_BYTES = 512_000;
 const WORKSPACE_FILES_MAX_OUTPUT_BYTES = 16 * 1024 * 1024;
 const GIT_CHECK_IGNORE_MAX_STDIN_BYTES = 256 * 1024;
 const STATUS_UPSTREAM_REFRESH_INTERVAL = Duration.seconds(15);
@@ -1602,6 +1603,46 @@ export const makeGitCore = Effect.fn("makeGitCore")(function* (options?: {
     },
   );
 
+  const readWorkingTreeDiff: GitCoreShape["readWorkingTreeDiff"] = Effect.fn("readWorkingTreeDiff")(
+    function* (cwd) {
+      // Check whether the repository has any commits yet.
+      const hasCommits = yield* executeGit(
+        "GitCore.readWorkingTreeDiff.hasCommits",
+        cwd,
+        ["rev-parse", "HEAD"],
+        { allowNonZeroExit: true, timeoutMs: 5_000, maxOutputBytes: 256 },
+      ).pipe(Effect.map((result) => result.code === 0));
+
+      if (hasCommits) {
+        // Standard case: diff HEAD covers staged + unstaged changes on tracked files.
+        const trackedDiff = yield* runGitStdoutWithOptions(
+          "GitCore.readWorkingTreeDiff.trackedDiff",
+          cwd,
+          ["diff", "HEAD", "--patch", "--minimal", "--no-color"],
+          {
+            maxOutputBytes: WORKING_TREE_DIFF_MAX_OUTPUT_BYTES,
+            truncateOutputAtMaxBytes: true,
+          },
+        );
+
+        return trackedDiff;
+      }
+
+      // No commits yet: show staged changes (initial add).
+      const stagedDiff = yield* runGitStdoutWithOptions(
+        "GitCore.readWorkingTreeDiff.stagedDiff",
+        cwd,
+        ["diff", "--cached", "--patch", "--minimal", "--no-color"],
+        {
+          maxOutputBytes: WORKING_TREE_DIFF_MAX_OUTPUT_BYTES,
+          truncateOutputAtMaxBytes: true,
+        },
+      );
+
+      return stagedDiff;
+    },
+  );
+
   const readConfigValue: GitCoreShape["readConfigValue"] = (cwd, key) =>
     runGitStdout("GitCore.readConfigValue", cwd, ["config", "--get", key], true).pipe(
       Effect.map((stdout) => stdout.trim()),
@@ -2134,6 +2175,7 @@ export const makeGitCore = Effect.fn("makeGitCore")(function* (options?: {
     pushCurrentBranch,
     pullCurrentBranch,
     readRangeContext,
+    readWorkingTreeDiff,
     readConfigValue,
     isInsideWorkTree,
     listWorkspaceFiles,

apps/server/src/git/Services/GitCore.ts

@@ -197,6 +197,11 @@ export interface GitCoreShape {
     baseBranch: string,
   ) => Effect.Effect<GitRangeContext, GitCommandError>;
 
+  /**
+   * Read a unified patch of working tree changes (staged + unstaged) on tracked files against HEAD.
+   */
+  readonly readWorkingTreeDiff: (cwd: string) => Effect.Effect<string, GitCommandError>;
+
   /**
    * Read a Git config value from the local repository.
    */

apps/server/src/ws.ts

@@ -660,6 +660,12 @@ const WsRpcLayer = WsRpcGroup.toLayer(
           git.initRepo(input).pipe(Effect.tap(() => refreshGitStatus(input.cwd))),
           { "rpc.aggregate": "git" },
         ),
+      [WS_METHODS.gitWorkingTreeDiff]: (input) =>
+        observeRpcEffect(
+          WS_METHODS.gitWorkingTreeDiff,
+          git.readWorkingTreeDiff(input.cwd).pipe(Effect.map((diff) => ({ diff }))),
+          { "rpc.aggregate": "git" },
+        ),
       [WS_METHODS.terminalOpen]: (input) =>
         observeRpcEffect(WS_METHODS.terminalOpen, terminalManager.open(input), {
           "rpc.aggregate": "terminal",