feat: enhance function calling with richer schemas, validation, parallel execution, and Ollama native support (#51)

* feat: add richer JSON Schema types and AJV validation utility

- Extended ToolParameter with enum, items, properties, additionalProperties (max depth 3)
- Added ToolError class with ToolErrorCategory enum
- Added ToolValidationError interface
- Created AJV-based validateToolArgs() with lazy loading and schema depth enforcement
- 57 new tests covering types and validation

* feat: add validation gate, parallel execution, and structured error feedback

- Arsenal.execute() validates args against JSON Schema before handler execution
- Tool execution errors categorized (scope_denied, tool_not_found, timeout, execution_error, validation_error)
- ToolError import fix in agent (was missing, causing silent ReferenceError)
- Semaphore-based parallel tool execution with configurable concurrency (default 5)
- Results maintain original call order regardless of completion order
- Structured error feedback to LLM with category only (no raw error messages)
- Scope/approval gates checked per-call before execution
- 35 new tests covering validation, parallel execution, and error feedback

* feat: add Ollama native function calling with probe + cache + fallback

- Added nativeTools config option to LLMConfig
- LocalAdapter probes model support for native tools on first call
- Probe result cached per model name to avoid re-probing
- Native tools formatted as Ollama /api/chat tools parameter
- Tool calls parsed from Ollama's tool_calls response format
- Falls back to text-based renderToolContract when native not supported
- OpenAI-compatible wire format also supported (for vLLM, LM Studio)
- 10 new tests covering probe, cache, fallback, and config overrides

* fix(tools): harden validation and native fallback

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Co-authored-by: sronaal <sronaal@users.noreply.github.com>
Co-authored-by: Joseph Magly <1159087+jmagly@users.noreply.github.com>

package-lock.json

@@ -10,6 +10,7 @@
       "license": "AGPL-3.0-or-later",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.25.1",
+        "ajv": "^8.20.0",
         "boxen": "^7.1.1",
         "chalk": "^5.3.0",
         "cli-table3": "^0.6.3",