docs: fix config drift (summarization/tokens/events) across main docs

[anilguleroglu]

What this PR fixes

Comprehensive docs pass to remove drift between implementation and documentation on main.

1) Summarization/token config naming drift

Replaced outdated references (limits.maxToken, contextTokenLimit, summaryTokenLimit) with current config:

• summarization.maxTokens
• summarization.summaryPromptMaxTokens

Updated in README + guide/reference pages + landing docs snippets.

2) Event/type docs drift

Updated API docs to match current event shape and runtime docs:

• tool_execution -> tool_call
• removed stale pause/resume event examples
• aligned examples with finalAnswer, metadata, progress, stream, cancelled

3) Broken/incorrect snippets

• fixed malformed AgentLimits block in docs/api/types.md
• updated code snippets in Getting Started/Index/README to use current summarization config

4) Architecture/Core docs consistency

Aligned architecture/core concepts and limits docs with current summarization lifecycle and option fields.

Files touched

• README.md
• docs/index.md
• docs/guide/getting-started.md
• docs/getting-started/README.md
• docs/guide/limits-tokens.md
• docs/guide/faq.md
• docs/faq/README.md
• docs/guide/architecture.md
• docs/architecture/README.md
• docs/core-concepts/README.md
• docs/api/agent.md
• docs/api/types.md

Notes

This PR is docs-only and does not change runtime behavior.