Grow a disarm/jtool2 `.matchers` file by mining XNU source for string literals that identify kernel functions, so more of a stripped kernelcache gets symbolicated. Scans a local XNU tree or fetches the matching tag from GitHub, derives `arg#|pattern|containing_function|calling_function` lines, verifies each pattern exists in the target kernel, and appends only new rules. Use when the user asks to "improve the matchers", "add matchers from source", "symbolicate more of the kernelcache", "update xnu.matchers", "find new matcher patterns", or points at a `.matchers` file and an XNU source tree.
