fix(codebase): optimize layout for editor view

- Removes top PageHeader to maximize vertical space.

- Sets layout padding tighter.

- Dynamically replaces 'Code files' header with the repository name (if single repo).

- Hides redundant nested tile header when there's only one codebase.

vibn-frontend/app/[workspace]/project/[projectId]/(home)/code/page.tsx

@@ -53,18 +53,23 @@ export default function CodeTab() {
         minHeight: "100vh",
         background: THEME.canvasGradient,
         fontFamily: THEME.font,
-        padding: "36px 48px",
+        padding: "24px",
       }}
     >
-      <div style={{ maxWidth: 1400, margin: "0 auto" }}>
+      <div
-        <PageHeader title="Codebase" />
+        style={{
+          maxWidth: "100%",
+          margin: "0 auto",
+          height: "calc(100vh - 48px)",
+        }}
+      >
         <Card
           padding={0}
           style={{
             overflow: "hidden",
             display: "flex",
             flexDirection: "column",
-            minHeight: "calc(100vh - 150px)",
+            height: "100%",
           }}
         >
           <div style={grid}>
@@ -104,7 +109,14 @@ export default function CodeTab() {
               {anatomy && (
                 <>
                   {/* Code Files */}
-                  <RailGroup title="Code files" count={codebases?.length ?? 0}>
+                  <RailGroup
+                    title={
+                      codebases?.length === 1
+                        ? codebases[0].label
+                        : "Code files"
+                    }
+                    count={codebases?.length ?? 0}
+                  >
                     {codebases && codebases.length === 0 && (
                       <RailEmpty>
                         {reason === "no_repo" ? (
@@ -134,33 +146,47 @@ export default function CodeTab() {
                             flex: 1,
                           }}
                         >
-                          <div
+                          {codebases.length > 1 && (
-                            style={{ ...tileHeader, padding: "20px 24px 12px" }}
+                            <div
-                          >
+                              style={{
-                            <span style={chevronCell}>
+                                ...tileHeader,
-                              <ChevronDown
+                                padding: "20px 24px 12px",
-                                size={13}
+                              }}
-                                style={{ color: THEME.mid }}
+                            >
+                              <span style={chevronCell}>
+                                <ChevronDown
+                                  size={13}
+                                  style={{ color: THEME.mid }}
+                                />
+                              </span>
+                              <Box
+                                size={14}
+                                style={{ color: THEME.mid, flexShrink: 0 }}
                               />
-                            </span>
+                              <div style={{ minWidth: 0, textAlign: "left" }}>
-                            <Box
+                                <div
-                              size={14}
+                                  style={{
-                              style={{ color: THEME.mid, flexShrink: 0 }}
+                                    fontSize: "0.95rem",
-                            />
+                                    fontWeight: 600,
-                            <div style={{ minWidth: 0, textAlign: "left" }}>
+                                    color: THEME.ink,
-                              <div
+                                  }}
-                                style={{
+                                >
-                                  fontSize: "0.95rem",
+                                  {cb.label}
-                                  fontWeight: 600,
+                                </div>
-                                  color: THEME.ink,
+                                {cb.hint && (
-                                }}
+                                  <div style={tileHint}>{cb.hint}</div>
-                              >
+                                )}
-                                {cb.label}
                               </div>
-                              {cb.hint && <div style={tileHint}>{cb.hint}</div>}
                             </div>
-                          </div>
+                          )}
-                          <div style={{ padding: "0 10px 24px 10px" }}>
+                          <div
+                            style={{
+                              padding:
+                                codebases.length > 1
+                                  ? "0 10px 24px 10px"
+                                  : "10px 10px 24px 10px",
+                            }}
+                          >
                             <GiteaFileTree
                               projectId={projectId}
                               rootPath={cb.path}