v1.8.0 "Tracepoint"

Fourth release of the RustyNES-parity roadmap: debugger depth II.

Added

• Memory Compare panel — captures a baseline snapshot of the Memory panel's current window
  and diffs it against the live window on every frame, showing only the rows that changed
  (before -> after hex). Flags a mismatch instead of a misleading diff if the window has
  scrolled since the baseline was captured (no scroll control exists yet — same gap the Memory
  panel itself carries).
• Docs panel — an in-app SNES-terminology glossary (docs/glossary.md, embedded via
  include_str!, ~3KB) for quick lookup mid-session, plus a link to the full MkDocs handbook
  (v1.6.0 "Lighthouse"). Deliberately scoped to the glossary alone, not the full 10-50KB
  subsystem-spec docs, to keep wasm size impact negligible (verified: +2KB gzip, still ~2.05 MiB
  under the 5 MiB budget).

Deferred (honestly scoped, not silently dropped)

• A call-stack view, an instruction/event trace buffer, and an inline 65816 assembler all need
  new core-side instrumentation (tracking call/return events or recording a trace log as they
  happen — not inferable from a point-in-time memory snapshot the way this rung's two panels are).
  A larger cross-crate change than this rung's frontend-only scope; tracked as follow-up work.
• A dedicated per-coprocessor-type register panel (DSP-2/4, S-DD1, CX4, OBC1, ST018, S-RTC beyond
  the SA-1/GSU state the existing Cart panel already shows) needs new Board-trait debug-state
  accessors — also deferred.