Unify AOML documents with the Info window's book navigation

Reuse the existing InfoWindowPresenter, InfoWindow.xml and registered Info window for AOML text:// and /showfile documents instead of opening standalone ChatPresenter reader windows. Document and item/character pages share bounded Back/Forward history. Following a new page after Back discards the forward branch, navigation preserves per-page scroll, first visits start at the top, and navigation boundaries disable the corresponding button. Preserve existing AOML rendering, natural images, selectable text, resize reflow and chatcmd dispatch through the normal command interpreter. Failed file reads must leave history unchanged. Existing chat-log readers remain independent. User clarified the missing links concern megatp/events.htm, not ARKTP. Inspected the actual Events source: under Rubi-Ka Zones only Aegean is an anchor; all remaining zone names and Shadowlands entries are plain text. This is a source-content limitation, not lost parser links; leave installation data unchanged. Additional supplied megatp/arktp.htm verification covers all 64 anchors via real-pointer clicks, including scrolled locations below Aegean. The installation lacks megatp/6101.txt and megatp/6102.txt; failed reads report without changing page/history. Verified nested file and text links, itemref links and mixed page history, bounded navigation, Back/Forward boundaries, forward-branch invalidation, failed reads preserving the current page/forward branch, per-page scroll restoration after resize, and scrolled pointer hit testing. Native Info-window screenshot with Back/Forward inspected. Build passed with zero warnings/errors; 3,626 client tests passed, 54 skipped (other RequiresInstall tests excluded); all 699 graphics tests passed. No live in-game interaction performed. Pull request: #2690 — https://git.project-rk.com/prk/engines/pulls/2690 Final combined branch validation: 3,628 client tests passed, 54 skipped (other RequiresInstall tests excluded), and 699 graphics tests passed.