fix(telegram): probe video dimensions through sdk

Fix Telegram portrait video distortion by probing video dimensions through the shared media helper and passing width/height to sendVideo.

Validation:
- Targeted Telegram/media tests passed locally.
- Plugin SDK API baseline check passed locally.
- Formatter and git diff whitespace checks passed locally.

CI note: current boundary drift observed on prior run came from existing src/plugin-sdk/discord.ts and src/plugin-sdk/telegram-account.ts, not this PR diff.

docs/plugins/sdk-migration.md

@@ -489,7 +489,7 @@ releases.
   | `plugin-sdk/provider-stream` | Provider stream wrapper helpers | `ProviderStreamFamily`, `buildProviderStreamFamilyHooks`, `composeProviderStreamWrappers`, stream wrapper types, and shared Anthropic/Bedrock/DeepSeek V4/Google/Kilocode/Moonshot/OpenAI/OpenRouter/Z.A.I/MiniMax/Copilot wrapper helpers |
   | `plugin-sdk/provider-transport-runtime` | Provider transport helpers | Native provider transport helpers such as guarded fetch, transport message transforms, and writable transport event streams |
   | `plugin-sdk/keyed-async-queue` | Ordered async queue | `KeyedAsyncQueue` |
-  | `plugin-sdk/media-runtime` | Shared media helpers | Media fetch/transform/store helpers plus media payload builders |
+  | `plugin-sdk/media-runtime` | Shared media helpers | Media fetch/transform/store helpers, ffprobe-backed video dimension probing, and media payload builders |
   | `plugin-sdk/media-generation-runtime` | Shared media-generation helpers | Shared failover helpers, candidate selection, and missing-model messaging for image/video/music generation |
   | `plugin-sdk/media-understanding` | Media-understanding helpers | Media understanding provider types plus provider-facing image/audio helper exports |
   | `plugin-sdk/text-runtime` | Shared text helpers | Assistant-visible-text stripping, markdown render/chunking/table helpers, redaction helpers, directive-tag helpers, safe-text utilities, and related text/logging helpers |