fix(planner): reply-language for infeasible_reason + answer-only-asked rule

fix(analyze_aggregate): reject non-string group_by (CASE/binning) keys

fix(planner): reject inlined table-ref as analyze_* data (Pattern A)

/fix planner and report (#13)

fix/ check (#12)

/fix validator and report (#10)

/fix check and help tool (#8)

feat/Knowledge & Data Tools (#3)

feat/Planner Agent (#2)