fix(detection): support bun.lock text format for Bun 1.2.0+ (#525)

Bun 1.2.0 changed the default lockfile from bun.lockb (binary) to
bun.lock (text format). Projects using newer Bun versions were being
incorrectly detected as npm because only bun.lockb was checked.

Updated 4 detection locations to check for both lockfile formats:
- project/stack_detector.py
- analysis/analyzers/framework_analyzer.py
- analysis/test_discovery.py
- core/workspace/git_utils.py (LOCK_FILES set)

Added test for bun.lock detection.

apps/backend/analysis/analyzers/framework_analyzer.py

@@ -408,6 +408,6 @@ class FrameworkAnalyzer(BaseAnalyzer):
             return "pnpm"
         elif self._exists("yarn.lock"):
             return "yarn"
-        elif self._exists("bun.lockb"):
+        elif self._exists("bun.lockb") or self._exists("bun.lock"):
             return "bun"
         return "npm"

apps/backend/analysis/test_discovery.py

@@ -275,7 +275,7 @@ class TestDiscovery:
             return "yarn"
         if (project_dir / "package-lock.json").exists():
             return "npm"
-        if (project_dir / "bun.lockb").exists():
+        if (project_dir / "bun.lockb").exists() or (project_dir / "bun.lock").exists():
             return "bun"
         if (project_dir / "uv.lock").exists():
             return "uv"

apps/backend/core/workspace/git_utils.py

@@ -22,6 +22,7 @@ LOCK_FILES = {
     "pnpm-lock.yaml",
     "yarn.lock",
     "bun.lockb",
+    "bun.lock",
     "Pipfile.lock",
     "poetry.lock",
     "uv.lock",

apps/backend/project/stack_detector.py

@@ -126,7 +126,7 @@ class StackDetector:
             self.stack.package_managers.append("yarn")
         if self.parser.file_exists("pnpm-lock.yaml"):
             self.stack.package_managers.append("pnpm")
-        if self.parser.file_exists("bun.lockb"):
+        if self.parser.file_exists("bun.lockb", "bun.lock"):
             self.stack.package_managers.append("bun")
         if self.parser.file_exists("deno.json", "deno.jsonc"):
             self.stack.package_managers.append("deno")

tests/test_discovery.py

@@ -80,6 +80,12 @@ class TestPackageManagerDetection:
         result = discovery.discover(temp_dir)
         assert result.package_manager == "bun"
 
+    def test_detect_bun_text_lockfile(self, discovery, temp_dir):
+        """Test bun detection via bun.lock (text format, Bun 1.2.0+)."""
+        (temp_dir / "bun.lock").write_text("")
+        result = discovery.discover(temp_dir)
+        assert result.package_manager == "bun"
+
     def test_detect_uv(self, discovery, temp_dir):
         """Test uv detection via uv.lock."""
         (temp_dir / "uv.lock").write_text("")