[BUG] Advanced Parsing: default parsing models are end-of-life, ingestion fails with 404 and syncs silently succeed

### Describe the bug

Enabling **Advanced Parsing** on a bot knowledge base breaks document ingestion for the default model choices, and the failure is silent: the sync can end up looking completed while zero documents were indexed, so the bot answers nothing from its knowledge.

Error from the `EmbeddingSynchronizeDataSourceHandler` logs:

```
[ERROR] ValidationException: An error occurred (ValidationException) when calling the
IngestKnowledgeBaseDocuments operation: Knowledge base role
arn:aws:iam:::role/AmazonBedrockExecutionRoleForKnowledgeBase... is not able
to call the specified model
arn:aws:bedrock:eu-central-2::foundation-model/anthropic.claude-3-5-sonnet-20240620-v1:0:
This model version has reached the end of its life. (Status Code: 404)
```

### Root cause

The parsing model allowlist (`backend/app/routes/schemas/bot_kb.py`):

```python
type_kb_parsing_model = Literal[
"anthropic.claude-3-5-sonnet-v1",
"anthropic.claude-3-haiku-v1",
"anthropic.claude-3-sonnet-v1",
"disabled",
]
```

* `anthropic.claude-3-5-sonnet-v1` and `anthropic.claude-3-sonnet-v1` have reached **end of life** on Bedrock: every ingestion using them fails with the 404 above.
* `anthropic.claude-3-haiku-v1` is the only option still invocable (verified via `list-foundation-models`: it is the last Claude model with `ON_DEMAND` inference), but it is a legacy early-2024 model.
* Simply bumping the list to newer models is not enough: **every current Claude model on Bedrock is `INFERENCE_PROFILE`-only**, so the parsing configuration would need inference-profile ARN support (and matching KB role permissions across the profile regions). Today `getParsingModel` in `cdk/lib/utils/bedrock-knowledge-base-args.ts` only builds base foundation-model references.

The frontend picker (`frontend/src/features/knowledgeBase/pages/BotKbEditPage.tsx`) exposes the same options. Verified at v3.17.0 and on current `v3` HEAD.

### Steps to reproduce

1. Create or edit a bot with a knowledge base.
2. Set Advanced Parsing Model to Claude 3.5 Sonnet v1 (the first non-disabled option).
3. Add a document and sync: ingestion fails ("This model version has reached the end of its life").
4. Workaround: set Advanced Parsing back to Disabled and the same documents ingest fine.

### Expected behavior

Advanced Parsing works with the offered models, and per-document ingestion failures surface in the bot sync status instead of failing silently.

### Suggested fix

1. Short term: stop offering the end-of-life models and keep stored bots deserializable → PR #1127.
2. Follow-up: support inference profiles for parsing (per the AWS docs on [parsing options](https://docs.aws.amazon.com/bedrock/latest/userguide/kb-advanced-parsing.html) and [supported models for parsing](https://docs.aws.amazon.com/bedrock/latest/userguide/knowledge-base-supported.html#knowledge-base-supported-parsing), current Claude / Nova vision families are supported parsers) so a current-generation model can be offered again.
3. Surface per-document `IngestKnowledgeBaseDocuments` failures in the sync status, and validate region availability of the configured parsing model.

Start with backend/app/routes/schemas/bot_kb.py and frontend/src/features/knowledgeBase/pages/BotKbEditPage.tsx to trace the parsing-model options, then read getParsingModel in cdk/lib/utils/bedrock-knowledge-base-args.ts. Check the EmbeddingSynchronizeDataSourceHandler ingestion path and its sync status handling. Done means end-of-life models are no longer offered while stored bots remain deserializable, supported parsing configuration works, and ingestion failures surface.

Written by the indexing model from the issue text.