fixing-code

# Fix and Diagnose Code Fix the requested defect or failing gate, one verified root cause at a time. Use the matching `writing-<lang>` skill for toolchain commands. The optional coding-posture plugin owns general debugging and fix procedure; this skill owns the defect evidence and regression contract. Do not load both just to repeat process steps. Without write access, return proposed changes (file, change, reason) instead of applying them. ## Hard rules - No fix without a reproducible pass/fail signal. If you cannot reproduce, ask for the missing artifact (logs, payload, trace, repro steps, environment) instead of patching on a guess. Ask before adding temporary instrumentation. - No destructive git (hard reset, clean, force push, checkout over local changes) and no `--no-verify`. - Never disable assertions, skip fast tests, lower lint severity, or ignore files to make a check pass or run faster. Clear caches only when a stale cache is the diagnosed cause. - Fix the requested failure first; ask before expanding to unrelated failures. ## Outcome - **Repro**: the fastest reliable failing signal, best a failing test at the behavior seam; otherwise a script, replayed payload, or small harness around the real path. - **Root cause**: traced from the failing boundary to the first bad state or contract mismatch, with evidence (`file:line`, symptom, tool). - **Regression test** at the seam where the user saw the bug. If only a shallow seam exists, say so rather than adding a fake-confidence helper test. - Remove temporary probes or promote them to regression tests. - Browser-only symptoms go to browser-automation unless a cheaper CLI or unit signal exists. - If a code-graph tool (GitNexus, codegraph) is installed and fresh, use it to find callers or impact before changing widely used code. Done when the original repro passes, the regression test passes (or the missing seam is reported), and the relevant build/test/lint checks pass on what you changed, or you name each check that did not run and why. ## Report Root cause with evidence, changes (`path:line — fix`), and each check with pass, fail, or skipped and why. If blocked, name the missing artifact, access, or approval. ## Platform additions No target-specific additions.