Add LegacyPolicyLoopStrategy and shared legacy patch utilities

[Bol-C14]

Motivation

• Support legacy workflows that supply either structured patch plans or full-netlist suggestions by mapping them into safe, param-only patches and running them through the unified attempt pipeline.
• Keep topology/guard invariants, stop reasons, and sim_runs accounting consistent with existing strategies and legacy reporting formats.

Description

• Add LegacyPolicyLoopStrategy in src/eesizer_core/strategies/legacy_policy_loop.py to run legacy-mapped CircuitSpecs with either an explicit legacy_patch_plan or a configurable policy, reusing attempt_pipeline.run_attempt and the standard guard chain and measurement flow.
• Factor legacy parsing/conversion helpers into src/eesizer_core/strategies/legacy_patch_utils.py providing extract_patch_plan, parse_patch_step, netlist_to_patch, and guard_failure_report to convert netlist-style steps into parameter-only Patch ops and to centralize validation logic.
• Refactor legacy_patch_plan to use the new utilities (extract_patch_plan, parse_patch_step, netlist_to_patch, guard_failure_report) instead of duplicate parsing logic, and export the new strategy from src/eesizer_core/strategies/__init__.py.
• Add docs: docs/devlog/2026-02-11_0900_legacy_policy_loop_strategy.md describing behavior and usage; preserve legacy-compatible history/report outputs via the existing LegacyReportOperator and manifest entries.

Testing

• No automated tests were executed as part of this change (no test run requested).

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Codex Task