feat: adding multiple files

### Added

- **Smart Scope Resolution** — Tree-sitter + indentation context for
selections
  - `resolve_selection_context()` in `scope/init.lua` handles partial
functions,
    whole functions, multi-function spans, indent blocks, and whole-file
selections
  - Enclosing function automatically sent as context when selecting code
inside one
  - Whole-file selection (>=80% of lines) triggers project tree as
context
  - Indentation-based fallback when Tree-sitter is unavailable

- **Explain-to-Document Intent** — "explain" prompts generate
documentation
  - Detects prompts like "explain this", "tell me about", "what does",
"question"
  - Generates documentation comments and inserts them above selected
code
  - Shows notification if nothing is selected
  - Updated intent action from "none" to "insert" for explain intent

- **Granular LLM Status Notifications** — Real-time progress reporting
  - Inline virtual text and floating status window show current stage
  - Stages: "Reading context...", "Searching index...", "Gathering
context...",
    "Recalling patterns...", "Building prompt...", "Sending to
[provider]...",
    "Processing response...", "Generating patch...", "Applying code..."
  - `update_inline_status()` in `thinking_placeholder.lua`
  - `update_stage()` in `thinking.lua`

- **Thinking Placeholder Positioning** — "Implementing..." appears above
selection
  - Uses `virt_lines_above = true` on extmark at selection start line
  - Dynamic status text updates during LLM processing

### Changed

- **Providers reduced to Copilot and Ollama only**
  - Removed Claude, OpenAI, and Gemini provider integrations
  - Deleted `llm/openai.lua` and `llm/gemini.lua`
  - Cleaned `llm/init.lua`, `config/defaults.lua`, `types.lua`,
`credentials.lua`,
    `cost/init.lua`, and `events/queue.lua` of all references
  - `valid_providers` now only includes "copilot" and "ollama"

- **Removed timer-based delayed processing** — Prompts are processed
instantly
  - Removed `timer` field, `timeout_ms`, and timer setup/cancellation
from `worker.lua`

- **Removed chat/agent/split window UI**
  - Deleted `ui/chat.lua`, `windows.lua`, `ui/switcher.lua`
  - Removed `CoderOpen`, `CoderClose`, `CoderToggle` commands
  - Removed window management from `autocmds.lua`, `inject.lua`,
`executor.lua`
  - Removed auto-open companion file logic

- **Commands removed from menu** (code retained with TODOs for
re-enabling)
  - `CoderAddApiKey`, `CoderRemoveApiKey`, `CoderBrain`,
`CoderFeedback`,
    `CoderMemories`, `CoderForget`, `CoderProcess`
  - Subcommands `process`, `status`, `memories`, `forget`,
`llm-feedback-good`,
    `llm-feedback-bad`, `add-api-key`, `remove-api-key` removed from
completion

### Fixed

- Fixed `patch.lua` syntax error — missing `if` wrapper around
SEARCH/REPLACE block
- Fixed `CoderModel` require path typo
(`codetyper.adapters.config.credentials`
  → `codetyper.config.credentials`)
- Fixed `thinking_placeholder` extmark placement appearing after
selection
  instead of above it

lua/codetyper/prompts/agents/intent.lua

@@ -44,10 +44,11 @@ Document any significant algorithmic changes.
 Output only the optimized code, no explanations.]],
 
 	explain = [[
-You are explaining code to a developer.
-Provide a clear, concise explanation of what the code does.
-Include information about the algorithm and any edge cases.
-Do not output code, only explanation.]],
+You are documenting code by adding documentation comments above it.
+Generate ONLY the documentation comment block (using the correct comment syntax for the file's language).
+Include: a brief description of what the code does, parameter types and descriptions, return type and description, and any important notes about edge cases or side effects.
+Do NOT include the code itself in your output — only the documentation comment block.
+Output nothing else.]],
 }
 
 return M