fix: normalize paths in ProjectByPath and add tilde expansion tests

ProjectByPath now expands both the input path and configured paths,
preventing silent mismatches when one side uses ~ and the other uses
an absolute path.

Added test cases exercising tilde expansion in both directions.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: maxbeizer

internal/config/config.go

@@ -567,9 +567,11 @@ func (c *Config) ExpandedProviderPath(provider string) string {
 }
 
 // ProjectByPath returns the ProjectConfig for the given path, or nil if not found.
+// Both the input path and configured paths are expanded to handle tilde notation.
 func (c *Config) ProjectByPath(path string) *ProjectConfig {
+	normalized := expandPath(path)
 	for i := range c.Projects {
-		if expandPath(c.Projects[i].Path) == path {
+		if expandPath(c.Projects[i].Path) == normalized {
 			return &c.Projects[i]
 		}
 	}

internal/config/config_test.go

@@ -604,10 +604,16 @@ func TestValidate_CustomTaskDuplicateType(t *testing.T) {
 }
 
 func TestProjectByPath(t *testing.T) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		t.Fatalf("failed to get home dir: %v", err)
+	}
+
 	cfg := &Config{
 		Projects: []ProjectConfig{
 			{Path: "/home/user/project-a", DraftPR: true},
 			{Path: "/home/user/project-b", DraftPR: false},
+			{Path: "~/project-c", DraftPR: true},
 		},
 	}
 
@@ -631,4 +637,19 @@ func TestProjectByPath(t *testing.T) {
 	if pc != nil {
 		t.Error("expected nil for nonexistent path")
 	}
+
+	// Tilde expansion: lookup with expanded path should match ~/project-c
+	pc = cfg.ProjectByPath(home + "/project-c")
+	if pc == nil {
+		t.Fatal("expected to find project-c via expanded path")
+	}
+	if !pc.DraftPR {
+		t.Error("expected DraftPR to be true for project-c")
+	}
+
+	// Tilde expansion: lookup with tilde should also match
+	pc = cfg.ProjectByPath("~/project-c")
+	if pc == nil {
+		t.Fatal("expected to find project-c via tilde path")
+	}
 }