rc-simplify-review

# Simplify Review Review the change set for over-engineering only, and report what can be cut. This is the complexity-only counterpart to `rc-code-review`: that skill asks "is this correct and safe?"; this one asks "did this need to exist, and what can be deleted?". The two are deliberately separate passes — a severity-ranked review files complexity findings as `low` and buries them under the criticals, so nobody acts on them. ## Code navigation (Serena) If the Serena MCP is available, prefer its symbolic tools over whole-file reads — they are LSP-accurate and token-efficient, and they are how you *prove* a cut is safe before proposing it: - `get_symbols_overview` to grasp a file's structure; `find_symbol` (by name path, e.g. `Type/method`) to jump to a definition. - `find_referencing_symbols` to confirm a symbol is genuinely dead, single-caller, or a one-product factory before flagging it for deletion. Never mark a cut from a name alone — a function may not do what its name says. Fall back to Grep/Glob + Read when Serena is unavailable or for plain-text searches. ## Required Inputs - None required. Defaults to the current change set against `main`. - Optional: specific files/directories to scope the pass, or a base ref to diff against (default `main`). To audit an existing codebase rather than a diff, the user names the directory to scan in full. ## Resolving the `.rc` base directory RC supports monorepos, where more than one `.rc` directory can exist. Before readin...