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>

pyproject.toml

@@ -63,6 +63,7 @@ homeassistant = ["aiohttp>=3.9.0,<4"]
 sms = ["aiohttp>=3.9.0,<4"]
 acp = ["agent-client-protocol>=0.9.0,<1.0"]
 mistral = ["mistralai>=2.3.0,<3"]
+bedrock = ["boto3>=1.35.0,<2"]
 termux = [
   # Tested Android / Termux path: keeps the core CLI feature-rich while
   # avoiding extras that currently depend on non-Android wheels (notably
@@ -108,6 +109,7 @@ all = [
   "hermes-agent[dingtalk]",
   "hermes-agent[feishu]",
   "hermes-agent[mistral]",
+  "hermes-agent[bedrock]",
   "hermes-agent[web]",
 ]