feat: evolve investigation into guided conversation

.claude/working-rules.md

@@ -66,6 +66,44 @@ Use a focused commit message.
 
 Do not merge or tag unless explicitly requested.
 
+## Non-narration rule
+
+Claude Code must act as an implementation agent, not narrate its internal
+debugging process.
+
+When tests fail:
+
+1. inspect the focused failure;
+2. make the smallest justified edit;
+3. rerun the focused test;
+4. repeat until passing or genuinely blocked.
+
+Do not print or explain intermediate reasoning.
+
+Never print:
+
+- rendered HTML;
+- full JSON;
+- full graph objects;
+- large diffs;
+- long stack traces;
+- repeated interpretations of the same failure.
+
+Prefer:
+
+tool → edit → focused test → concise report
+
+The final chat response must be under 1,000 words and normally contain only:
+
+- branch;
+- commit hash;
+- files changed;
+- behaviour changed;
+- tests;
+- lint/build;
+- remaining limitation;
+- git status.
+
 ## Response discipline
 
 At the end of a task, normally report only: