fix(gui): keep the log tail-scroll at the true bottom with wrapping - #549

Follow-up to #548, which moved the amuleGUI log panes to wxStyledTextCtrl (Scintilla). This fixes the auto-scroll-to-bottom landing short when log lines wrap.

Background

With word-wrap on, Scintilla lays out wrapped lines incrementally over several idle cycles (wrapping tens of thousands of lines is expensive, so it doesn't block). The tail-scroll ran once, before that layout finished, so it computed against a display-line count that didn't yet include the still-unwrapped tail and stopped short. It only reproduced when lines actually wrap — @ghysler pinned it to window width (short at 1280px where his lines wrap two-up, correct at 2560px where they don't).

A first attempt (re-scroll on idle until the position settles) fixed the switch-in-after-load case but not switch-in-mid-load: while the log was still replaying, each poll's batch also scrolled directly, and the idle loop — which watches the scroll position to tell a manual scroll from an append — misread the batch's own scroll as a manual scroll and gave up, so the final one-shot scroll landed at ~90%.

Fix

Make OnInternalIdle() the sole scroller: ScrollToBottom() only sets a pending flag, and the idle loop re-applies ScrollToEnd() until the first-visible line stops moving (wrap settled at the true bottom), bailing only when the view moves on its own (a genuine manual scroll). Since appends never move the first-visible line, the loop follows the growing log through the whole replay. It lives in the base CMuleLogCtrl, so all three panes (aMule Log, aMuleGUI Log, server info) share it.

Also corrects a few comments from #548 that the rework left inaccurate (comment-only).

Test plan

Verified against a live remote daemon with a large multi-day log (~16k lines), on a narrow window so lines wrap:

• Switch to Networks after load finishes → lands at the bottom
• Switch to Networks mid-load (watching the replay) → lands at the bottom
• Scroll up to read history → stays put; returning to the bottom re-tails
• aMuleGUI Log and server-info panes behave the same

Lint: clang-format clean; clang-tidy Tier-1 + Tier-2 diff checks both clean.