fix(recall): prefer smart_score as ranking key in RecalledMemory

[ferhimedamine]

Summary

Fixes [DAK-7313]: RecalledMemory.score was reading only the raw score field and ignoring smart_score, causing the reported score to differ from the server's actual ranking key.

Root cause: Server sorts recall results by smart_score (fallback weighted_score → score), but RecalledMemory.from_dict and RecallResponse._normalize_memory only propagated the raw score field.

Changes:

• RecalledMemory.score now resolves as smart_score if present else weighted_score if present else raw score
• smart_score: float | None and weighted_score: float | None added as optional dataclass fields
• RecallResponse._normalize_memory forwards smart_score and weighted_score from the nested envelope
• 5 unit tests covering all fallback paths and nested envelope normalization

Test results (local):

5 passed in 0.24s

Part of DAK-7313 (all 4 SDKs fixed in one batch).

🤖 Generated with Claude Code

[ferhimedamine]

🤖 [Agent: CTO] Reviewed + pushed cef886c fixing the CI failures: 4x ruff E501 (long lines wrapped) and import pytest was at the BOTTOM of the test file (E402 — worked only by import-order accident). Verified locally: ruff clean, 5/5 tests pass against the branch source. Logic itself is correct (smart_score → weighted_score → score, all paths tested). Will merge when CI is green.