Fix: Improve Anthropic / Claude API support (#62)

* Fix: Improve Anthropic / Claude API support

- Add tool call collection in non-streaming Anthropic messages
- Implement system prompt normalization ([System]: prefix)
- Fix token counting to use resolved model instance
- Add Claude model name fuzzy matching (date suffix stripping, separator normalization)
- Implement /v1/messages/count_tokens endpoint for token pre-counting
- Add GET / and HEAD / root endpoint handlers for health probes
- Add image placeholder handling for tool_result blocks

* Improve dashboard performance and gateway lifecycle

* Fix request IP tracking leak and add regression validation

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Co-authored-by: lxh721 <152139706+lxh721@users.noreply.github.com>

Author: gallexy-liu

.gitignore

@@ -1,3 +1,10 @@
 node_modules
 .tsbuildinfo
 dist/
+perf-results/
+.vscode-test/
+.claude/
+out/
+*.vsix
+*.cpuprofile
+bun.lock