fix(telegram): keep MarkdownV2 on flood finalize edits

[rsk-731]

Summary

• Telegram finalize edits treated flood control / RetryAfter like a MarkdownV2 parse failure and fell back to plain text.
• That made final replies look unrendered after rate limits (common when streaming/progress spam trips flood control).
• Flood errors now re-raise into the existing wait/retry path; short floods retry still as MarkdownV2; plain fallback stays for real parse failures only.
• Added regression tests in tests/gateway/test_telegram_format.py.

Root cause

In TelegramAdapter.edit_message(finalize=True), the MarkdownV2 edit_message_text except-block stripped formatting on any error, including:
Flood control exceeded. Retry in N seconds

Test plan

• pytest tests/gateway/test_telegram_format.py::TestEditMessageStreamingSafety -q
• pytest tests/gateway/test_telegram_final_delivery.py::test_telegram_long_flood_result_keeps_retry_after -q
• Manual: enable TG streaming, trip a short flood, confirm finalize still has bold/code (or clean flood fallback send with MarkdownV2), not stripped plain

Notes

Operational mitigation still useful on busy bots: keep Telegram tool_progress / streaming quiet to avoid flooding the Bot API.

[alt-glitch]

This was generated by AI during triage.

Duplicate of #52933: both preserve MarkdownV2 for transient Telegram flood-control errors instead of treating them as parse failures. #52933 is the broader open repair for the same final/overflow edit policy.

[teknium1]

Thanks for isolating the normal finalized-edit failure: current main still catches every MarkdownV2 edit error and strips formatting (plugins/platforms/telegram/adapter.py:4768-4790).

Problems

• The overflow change does not actually enter the existing edit retry handler. The preflight path returns _edit_overflow_split(...) directly (plugins/platforms/telegram/adapter.py:4734-4738); that helper catches the reraised error and returns a generic failure without retry_after (plugins/platforms/telegram/adapter.py:4969-4980). The proposed overflow re-raise therefore avoids the immediate plain fallback but neither retries as MarkdownV2 nor preserves Telegram's requested delay.
• The new tests cover normal finalized edits only. Add coverage for the overflow first-chunk flood path, which currently has the parallel plain fallback at plugins/platforms/telegram/adapter.py:4944-4962.

Suggested changes

• Classify and propagate flood-control failures inside _edit_overflow_split, including retry_after, or perform its bounded MarkdownV2 retry there.
• Consolidate this with the broader open fix(telegram): stabilize streamed overflow markdown delivery #52933 overflow/final-delivery repair.

Automated hermes-sweeper review.