Add page --all full-page reading mode with scroll settling

[Copilot]

page only returned one viewport slice at a time, which made long or lazy-rendered pages incomplete unless callers manually paged through them. This change adds a CLI-orchestrated full-page mode that walks the page, waits for lazy content to render, and returns one aggregated reading view.

• CLI surface

  • Added browser-cli page <session-id> --all
  • Added --settle <ms> for per-scroll delay in --all mode (500ms default)
  • Enforced flag exclusivity: --all cannot be combined with -p, --next, or --prev
  • Restricted --settle to --all

• Full-page capture flow

  • Reuses existing SCROLL + GET_PAGE_FRESH actions from the CLI
  • Captures the initial snapshot, records original scroll_top, then iterates logical pages
  • Recomputes total_pages from each fresh snapshot so page growth from lazy loading is picked up
  • Restores the original scroll position after aggregation

• Aggregation behavior

  • Parses each page with existing page-structure logic instead of merging raw DOM snapshots
  • Appends per-page nodes into a single reading-oriented PageData
  • Applies light leading-duplicate suppression across page boundaries to reduce sticky-header repetition
  • Reindexes output IDs and normalizes metadata to:
    • current_page = 1
    • total_pages = 1
    • truncated = false

• Docs

  • Updated README.md, README.en.md, and SKILL.md with --all / --settle usage and guidance that --all is intended for reading, not follow-up element targeting

browser-cli page s123 --all
browser-cli page s123 --all --settle 1000 --json