feat(runtime): add planner reflection history with rationale and thinking

- ToolCallDecision captures thinking blocks and pre-tool text output
- AnthropicToolCallingClient supports optional extended thinking (budget_tokens + beta header)
- PlannedStep carries rationale and thinking from each LLM decision
- WorldEvent replaces scene_summary with rationale/thinking/page fields (backward-compatible)
- AI planner system prompt instructs reflection before each tool call
- _history_summary() emits compact {page, rationale, action, success} dicts
- Cloud DB migration 0011 adds nullable rationale/thinking columns to planner_decision_log
- OpenAI client extracts reasoning_content into thinking field

packages/cloud-platform/cloud/migrations/versions/0011_planner_decision_log_reflection.py

@@ -0,0 +1,27 @@
+"""Add rationale and thinking columns to planner_decision_log."""
+
+from __future__ import annotations
+
+import sqlalchemy as sa
+from alembic import op
+
+revision = "0011_planner_decision_log_reflection"
+down_revision = "0010_skill_management"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "planner_decision_log",
+        sa.Column("rationale", sa.Text(), nullable=True),
+    )
+    op.add_column(
+        "planner_decision_log",
+        sa.Column("thinking", sa.Text(), nullable=True),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("planner_decision_log", "thinking")
+    op.drop_column("planner_decision_log", "rationale")