Profiler gets one-click browser serving

Lean can now serve trace.profiler output in a browser (654017f)

A new trace.profiler.serve flow exports the Firefox Profiler JSON, serves it from an ephemeral 127.0.0.1 HTTP server, and opens the viewer URL automatically. This removes the manual file-upload step and makes profiler inspection much faster.

grind now reports local E-matching theorems more clearly (2674a13)

Diagnostics for grind no longer drop local hypotheses or hide them behind anonymous local.<idx> names. Local theorem origins now preserve user-facing names and instantiation counters, which should make solver output much easier to interpret.

Vector append lemmas were generalized to mixed lengths (a71f158)

Several Vector lemmas about ++ now accept vectors of different size indices instead of requiring both sides to share the same n. That broadens reuse for sum, prod, flatMap, unattach, and eraseIdx lemmas and reduces unnecessary casting friction.

Other misc changes

• Marked move/swap operations noexcept for type_checker, mpz, and name_generator to help STL/container usage (62142c5)
• Updated stage0 generated sources twice, including a new profiler server artifact and a prefer_native flag flip (0eb80e3, 805fbca)