docs: Add Screen Reader Speed to PRODUCT.md and ARCHITECTURE.md

[Copilot]

PR #33 adds OnScreenReaderSpeedChanged(uint8_t speed) notification handler and the screenReaderSpeed persistence key — neither was reflected in documentation.

Changes

• PRODUCT.md: Added Screen Reader Speed as an Accessibility Feature
• ARCHITECTURE.md:
  • Settings count 18 → 19
  • Added screenReaderSpeed (uint8_t, key: "screenReaderSpeed") to Accessibility Settings
  • Added OnScreenReaderSpeedChanged to the full notification events list

SME Review Needed

• Default value and valid range for screenReaderSpeed (uint8_t) — not yet defined in the implementation layer
• Clarify whether Screen Reader Speed is a distinct capability from Voice Guidance Rate (double, 0.1–10×) or overlaps for certain assistive stacks

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 --json name --jq .name (http block)
• https://api.github.com/repos/melhar098/entservices-usersettings/issues/56/comments
  • Triggering command: /usr/bin/curl curl -s -o /dev/null -w %{http_code} -X POST -H Authorization: ****** -H Content-Type: application/json REDACTED -d {"body": "test"} (http block)
• https://api.github.com/repos/rdkcentral/entservices-usersettings
  • Triggering command: /usr/bin/curl curl -s -H Authorization: ****** REDACTED (http block)
• https://api.github.com/repos/rdkcentral/entservices-usersettings/pulls
  • Triggering command: /usr/bin/curl curl -s -X POST -H Authorization: ****** -H Content-Type: application/json REDACTED -d { "title": "[DOCS] Documentation updates for PR #33 - Screen Reader Speed feature", "head": "melhar098:copilot/doc-guardian-update-docs-again", "base": "develop", "body": "## Documentation Updates for PR #33 - Screen Reader Speed Feature\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)