[BUG][code-analyzer] <Unexpected Flow Engine Failure on metadata retrieved using API v68>

### Have you tried to resolve this issue yourself first?

- [x] I confirm I have gone through the above steps and still have an issue to report.

### Bug Description

1. Flow metadata is retrieved using API v68.0
2. As per Winter'27 release, End Elements are stored in metadata now. [Here](https://help.salesforce.com/s/articleView?id=release-notes.rn_automate_flow_builder_end_elements_saved_to_metadata_264.htm&release=264&type=5).
3. Metadata contains tags
4. sf code analyzer execution fails with a critical warning The engine with name 'flow' threw an unexpected error: Error: ENOENT:

### Output / Logs

```shell
The engine with name 'flow' threw an unexpected error: Error: ENOENT: no such file or directory, open '.../flow/flowScannerResultsFile.json'
at async open (node:internal/fs/promises:638:25)
at async Object.readFile (node:internal/fs/promises:1242:14)
at async RunTimeFlowScannerCommandWrapper.runFlowScannerRules (.../code-analyzer-flow-engine/dist/python/FlowScannerCommandWrapper.js:52:36)
...
The engine's own debug log (sfca-flow-*.log, only written when log_folder is set) shows the actual root cause:
flow_parser.parse | CRITICAL | Variable type cannot find match for elem with tag ends
flow_parser.parse | CRITICAL | non-traversable element in flow
```

### Steps To Reproduce

1. Take a sample flow which is extracted using v68.0 API (Attached a sample)
2. Run sf code-analyzer run --workspace --rule-selector flow
3. crashes with UnexpectedEngineError as above.
4. Delete the block and the referencing it (leave the assignment's path unconnected — functionally identical, implicit end) → scan succeeds normally

Also reproduced on a real-world flow (happy to attach if useful) with two independent paths converging on a single named End element (END_ELEMENT_2) — same crash, same fix by removing the End element.

[Minimal_Test.flow-meta.xml](https://github.com/user-attachments/files/32262748/Minimal_Test.flow-meta.xml)

### Expected Behavior

The flow engine should be able to parse and analyze Flows containing explicit elements without crashing, and any per-file engine failure during a multi-file scan should be surfaced as a visible error/violation rather than silently dropped.

### Operating System

Windows 11

### Salesforce CLI Version

2.75.5

### Code Analyzer Plugin (code-analyzer) Version

5.16.0

### Node Version

_No response_

### Java Version

_No response_

### Python Version

3.12.10

### Additional Context (Screenshots, Files, etc)

_No response_

### Workaround

Extract metadata using v67.0 API

### Urgency

Moderate

添付された Minimal_Test.flow-meta.xml と flow ルールセレクターを使って sf code-analyzer を実行し、失敗を再現します。code-analyzer-flow-engine/dist/python/FlowScannerCommandWrapper.js と flow_parser.parse のデバッグ出力を読みます。明示的な 要素が正常にスキャンされ、複数ファイルのスキャン中にファイルごとのエンジン障害が報告されれば完了です。

索引モデルが issue の本文から書いたものです。