docs: Add screenReaderSpeed setting to ARCHITECTURE.md and PRODUCT.md

[Copilot]

PR #33 added OnScreenReaderSpeedChanged event handler and USERSETTINGS_SCREEN_READER_SPEED_KEY for a new screenReaderSpeed accessibility setting, but neither ARCHITECTURE.md nor PRODUCT.md reflected this addition.

Changes

• ARCHITECTURE.md — Updated settings count 18 → 19; added screenReaderSpeed (uint8) to Accessibility Settings list
• PRODUCT.md — Added "Screen reader speed configuration for accessibility tools" to Accessibility Features

SME Review Needed

• Default value and valid range for the uint8 speed parameter (not in PR changes to test doc agent #33 diff)
• Confirm SetScreenReaderSpeed/GetScreenReaderSpeed implementations are in scope

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/graphql
  • Triggering command: /usr/bin/gh gh repo view --json parent --jq .parent | "\(.owner.login)/\(.name)" (http block)
  • Triggering command: /usr/bin/gh gh repo view --json owner --jq .owner.login (http block)
  • Triggering command: /usr/bin/gh gh repo view melhar098/entservices-usersettings --json viewerPermission --jq .viewerPermission (http block)
• https://api.github.com/repos/melhar098/entservices-usersettings/pulls
  • Triggering command: /usr/bin/curl curl -s -o /tmp/pr_result.json -w %{http_code} -X POST -H Accept: application/vnd.github+json -H Authorization: ****** -H X-GitHub-Api-Version: 2022-11-28 REDACTED -d { "title": "[DOCS] Documentation updates for PR #33", "body": "## Documentation Updates\n\nThis PR updates the documentation to reflect the changes introduced in PR #33 (changes to test doc agent).\n\n### Changes Made\n\n#### ARCHITECTURE.md\n (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)