Add LSP rename (Phase 3) and update AGENTS.md with future work

- F2 keybinding triggers prepareRename at cursor
- Shows inline text input pre-filled with current symbol name
- Enter confirms and applies workspace edits across all occurrences
- Escape cancels the rename
- Full flow: prepareRename → input → rename → apply edits
- AGENTS.md: document inline token/cache/cost stats feature idea
- AGENTS.md: document rename implementation for reference

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

AGENTS.md

@@ -32,3 +32,49 @@ The project must always have a **clean build with zero warnings and zero errors*
 - `app/src/code/completion.rs` — extend the completion state machine with an LLM provider
 - `crates/ai/` — existing Bedrock/LLM infrastructure can be reused
 - Editor decoration system — for rendering ghost text (similar to inlay hints)
+
+---
+
+## Inline Token/Cache/Cost Stats on LLM Responses
+
+**Idea:** Display context window usage, cache hit percentage, and cost as a compact footer below each completed LLM response in the agent conversation view. This replaces the "context" button on the bottom-right of the input area.
+
+**Data to display (per response):**
+- Context usage: percentage used, input tokens / context window size (e.g., "Context: 45.2% (20.6k / 200k)")
+- Cache hit stats: hit percentage with breakdown (e.g., "Cache Hit: 89.3% (R: 18.4k, W: 1.2k, M: 1.0k)")
+- Cost: cumulative session cost (e.g., "Cost: $0.42")
+
+**Data source:**
+- Bedrock `InvokeModel`/`Converse` response metadata contains:
+  - `usage.input_tokens` — tokens sent (cache misses)
+  - `usage.cache_read_input_tokens` — tokens served from cache
+  - `usage.cache_creation_input_tokens` — tokens written to cache
+  - `usage.output_tokens` — tokens generated
+- Cache hit % = `cache_read / (cache_read + cache_write + input_tokens) * 100`
+
+**Reference implementation:**
+- `~/.claude/statusline-command.sh` — shell script that formats these exact metrics for Claude Code's status line. Same formula and human-readable formatting (k/M suffixes) should be used.
+
+**UI approach:**
+- Render as a single-line or two-line muted footer below each AI response block
+- Use dimmed/secondary text color, monospace font, compact layout
+- Remove the "context" icon button from the input area bottom-right since this replaces it
+
+**Integration points in Galaxy:**
+- Find where Bedrock response `usage` metadata is captured after each streaming response completes
+- Find the conversation block rendering (where each AI response ends) to add the footer element
+- `app/src/ai/blocklist/` — likely where response blocks are rendered
+- `crates/ai/` — where Bedrock API responses are parsed
+
+---
+
+## LSP Rename (Phase 3 - App Wiring)
+
+**Status:** LSP layer is complete (`prepare_rename` + `rename` methods exist on LspServerModel). Needs app-layer wiring.
+
+**Implementation needed:**
+- F2 keybinding triggers `prepareRename` at cursor position
+- If valid, show an inline text input overlay at the symbol location pre-filled with the current name
+- On confirm (Enter), send `rename` request with the new name
+- Apply the resulting `WorkspaceEdit` to the editor (single-file for now)
+- On cancel (Escape), dismiss the input overlay