Improve base family failure hints

[SilverSupplier]

Summary

• Rewrite base spell failure reasons as player-facing action guidance.
• Add wind-specific checks and hints for stroke count, parallel direction, and spacing.
• Clarify life-symbol feedback around stem, branch, and split-point structure.
• Tighten review findings so extra-stroke wind casts stay incomplete and successful life casts keep positive next-hint copy.

Verification

• Unity EditMode tests: 29 passed
• Unity PlayMode tests: 6 passed
• node scripts/validate-doc-state.mjs
• GitHub build, test, validate-docs, and codeql checks

Notes

• This PR is scoped to base family failure copy and target-family-specific hint behavior for [Child #14] base family별 실패 힌트 문구 개선 #38.
• It intentionally avoids overlay feedback changes, which are handled in Improve overlay failure hints #59.

Closes #38