refactor: fold remaining extension-flow wrappers through _exec_logged

[hunnyboy1217]

Closes #305

Summary

Direct follow-on to #91, which standardized 23 write wrappers through _exec_logged but left the six propose/challenge/finalize wrappers for reservation and swap-timeout extensions out of scope. Those six were skipped because four of them pass wait_for_inclusion=False — a parameter the helper didn't accept.

This PR extends _exec_logged with wait_for_inclusion: bool = True and collapses the six remaining wrappers to single return self._exec_logged(...) delegations. Default True preserves byte-identical behavior for the 23 callers already routed through the helper; the four no-wait sites pass the kwarg explicitly.

Motivation

• Single source of truth for write-side extrinsic submission — these six were the only write paths that could drift independently from _exec_logged (e.g., if pre-flight balance probing or log wording evolves).
• Lower-friction extension — future propose/challenge/finalize triples inherit the one-line shape instead of resurrecting the 5-line block.
• Smaller surface area — duplication eliminated; public signatures, log-message wording, and the wait_for_inclusion=False semantics documented at allways/contract_client.py:529-535 are preserved.

Changes

• allways/contract_client.py:
  • _exec_logged (L1009-L1027): added wait_for_inclusion: bool = True kwarg, threaded through to exec_contract_raw
  • Collapsed six wrappers (L1067-L1131) to single delegations:
    • Reservation extension: propose_extend_reservation (no-wait), challenge_extend_reservation (no-wait), finalize_extend_reservation (waits)
    • Timeout extension: propose_extend_timeout (no-wait), challenge_extend_timeout (no-wait), finalize_extend_timeout (waits)
  • Net +32 / −37 (−5 LOC plus removal of all duplication)

Type of Change

• Refactoring (consolidation, no behavior change)

Test plan

• uv run pytest tests/ — 411 passed
• uv run pytest tests/test_optimistic_extensions.py — 31 passed (covers all six wrappers)
• uv run ruff check allways/ neurons/ — all checks passed
• uv run ruff format --check allways/contract_client.py — already formatted
• uv run pre-commit run --files allways/contract_client.py — all hooks passed
• Public signatures, log-message wording, and wait_for_inclusion semantics preserved — verified by diff review