feat: Add indexing group to CodexLens environment variable schema

- Introduced a new `indexing` group in the environment variable schema with fields for AST grep usage, static graph enablement, and relationship types.
- Updated the CodexLens configuration to support new indexing features.

feat: Enhance DashboardToolbar with session and fullscreen controls

- Added props for session sidebar visibility and fullscreen mode to the DashboardToolbar component.
- Implemented handlers for toggling session sidebar and fullscreen mode.
- Updated the toolbar layout to include session sidebar toggle and fullscreen button.

refactor: Improve TerminalGrid and TerminalPane components

- Refactored GridGroupRenderer to handle pane size changes directly via store.
- Enhanced TerminalPane to remove unused file browser logic and improve layout handling.
- Updated key generation for child panes to ensure stability.

feat: Extend CodexLens API for staged Stage-2 expansion modes

- Added support for `staged_stage2_mode` in the CodexLens API, allowing for different expansion strategies.
- Updated semantic search handlers to process new stage-2 mode parameter.
- Implemented validation and handling for new stage-2 modes in the backend.

test: Add benchmarks for staged Stage-2 modes comparison

- Created a benchmark script to compare performance and results of different staged Stage-2 modes.
- Included metrics for latency, overlap, and diversity across modes.

codex-lens/src/codexlens/api/semantic.py

@@ -24,6 +24,7 @@ def semantic_search(
     structural_weight: float = 0.3,
     keyword_weight: float = 0.2,
     fusion_strategy: str = "rrf",
+    staged_stage2_mode: Optional[str] = None,
     kind_filter: Optional[List[str]] = None,
     limit: int = 20,
     include_match_reason: bool = False,
@@ -50,6 +51,10 @@ def semantic_search(
             - binary: Binary rerank cascade -> binary_cascade_search
             - hybrid: Binary rerank cascade (backward compat) -> binary_rerank_cascade_search
             - dense_rerank: Dense rerank cascade -> dense_rerank_cascade_search
+        staged_stage2_mode: Optional override for staged Stage-2 expansion mode
+            - precomputed: GraphExpander over per-dir graph_neighbors (default)
+            - realtime: Live LSP expansion (requires LSP availability)
+            - static_global_graph: GlobalGraphExpander over global_relationships
         kind_filter: Symbol type filter (e.g., ["function", "class"])
         limit: Max return count (default 20)
         include_match_reason: Generate match reason (heuristic, not LLM)
@@ -97,6 +102,17 @@ def semantic_search(
     # Load config
     config = Config.load()
 
+    # Optional per-call override for staged cascade Stage-2 mode.
+    if staged_stage2_mode:
+        stage2 = str(staged_stage2_mode).strip().lower()
+        if stage2 in {"live"}:
+            stage2 = "realtime"
+        valid_stage2 = {"precomputed", "realtime", "static_global_graph"}
+        if stage2 in valid_stage2:
+            config.staged_stage2_mode = stage2
+        else:
+            logger.debug("Ignoring invalid staged_stage2_mode: %r", staged_stage2_mode)
+
     # Get or create registry and mapper
     try:
         registry = RegistryStore.default()