feat: native AWS Bedrock provider via Converse API

Salvaged from PR #7920 by JiaDe-Wu — cherry-picked Bedrock-specific
additions onto current main, skipping stale-branch reverts (293 commits
behind).

Dual-path architecture:
  - Claude models → AnthropicBedrock SDK (prompt caching, thinking budgets)
  - Non-Claude models → Converse API via boto3 (Nova, DeepSeek, Llama, Mistral)

Includes:
  - Core adapter (agent/bedrock_adapter.py, 1098 lines)
  - Full provider registration (auth, models, providers, config, runtime, main)
  - IAM credential chain + Bedrock API Key auth modes
  - Dynamic model discovery via ListFoundationModels + ListInferenceProfiles
  - Streaming with delta callbacks, error classification, guardrails
  - hermes doctor + hermes auth integration
  - /usage pricing for 7 Bedrock models
  - 130 automated tests (79 unit + 28 integration + follow-up fixes)
  - Documentation (website/docs/guides/aws-bedrock.md)
  - boto3 optional dependency (pip install hermes-agent[bedrock])

Co-authored-by: JiaDe WU <40445668+JiaDe-Wu@users.noreply.github.com>

agent/error_classifier.py

@@ -112,6 +112,10 @@ _RATE_LIMIT_PATTERNS = [
     "please retry after",
     "resource_exhausted",
     "rate increased too quickly",  # Alibaba/DashScope throttling
+    # AWS Bedrock throttling
+    "throttlingexception",
+    "too many concurrent requests",
+    "servicequotaexceededexception",
 ]
 
 # Usage-limit patterns that need disambiguation (could be billing OR rate_limit)
@@ -171,6 +175,11 @@ _CONTEXT_OVERFLOW_PATTERNS = [
     # Chinese error messages (some providers return these)
     "超过最大长度",
     "上下文长度",
+    # AWS Bedrock Converse API error patterns
+    "input is too long",
+    "max input token",
+    "input token",
+    "exceeds the maximum number of input tokens",
 ]
 
 # Model not found patterns