feat: add function completion, apply delay, and VimLeavePre cleanup

Major improvements to the event-driven prompt processing system:

Function Completion:
- Override intent to "complete" when prompt is inside function/method scope
- Use Tree-sitter to detect enclosing scope and replace entire function
- Special LLM prompt instructs to complete function body without duplicating
- Patch apply uses "replace" strategy for scope range instead of appending

Apply Delay:
- Add `apply_delay_ms` config option (default 5000ms) for code review time
- Log "Code ready. Applying in X seconds..." before applying patches
- Configurable wait time before removing tags and injecting code

VimLeavePre Cleanup:
- Logs panel and queue windows close automatically on Neovim exit
- Context modal closes on VimLeavePre
- Scheduler stops timer and cleans up augroup on exit
- Handle QuitPre for :qa, :wqa commands
- Force close with buffer deletion for robust cleanup

Response Cleaning:
- Remove LLM special tokens (deepseek, llama markers)
- Add blank line spacing before appended code
- Log full raw LLM response in logs panel for debugging

Documentation:
- Add required dependencies (plenary.nvim, nvim-treesitter)
- Add optional dependencies (nvim-treesitter-textobjects, nui.nvim)
- Document all intent types including "complete"
- Add Logs Panel section with features and keymaps
- Update lazy.nvim example with dependencies

Tests:
- Add tests for patch create_from_event with different strategies
- Fix assert.is_true to assert.is_truthy for string.match

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lua/codetyper/config.lua

@@ -46,6 +46,7 @@ local defaults = {
     escalation_threshold = 0.7, -- Below this confidence, escalate to remote LLM
     max_concurrent = 2, -- Maximum concurrent workers
     completion_delay_ms = 100, -- Wait after completion popup closes
+    apply_delay_ms = 5000, -- Wait before removing tags and applying code (ms)
   },
 }