Phase 4 modernization: UUID-based sprite tracking + listener adoption

[Chrizhermann]

Deferred Phase 4 from #40 (EEex v1.0.0 upgrade umbrella). UUID adoption is also the partial enabler for #19 (clones/summons as casters), so this should land before #19's full feature work.

Scope

UUID-based sprite identity

Replace party-slot-index identity in BfBot.Exec._casters[] and persistence payloads with EEex_Sprite_GetUUID / EEex_Sprite_GetFromUUID. Survives party reorder mid-cast and save reload without sprite-pointer staleness.

• BfBotExe._Advance caster resolution — currently caches CGameSprite userdata, freed across save reload (cf. Crash: pressing Stop after reloading a save mid-cast #38 fix, which works around this via name-comparison heuristics in _IsStateStale). UUID would resolve cleanly across reloads.
• BfBotPer marshal payload — UUID lookups for cross-character preset references (e.g. spells targeting a specific name).

Actionbar listener

Adopt EEex_Actionbar_AddButtonsUpdatedListener in BfBotScn to refresh the cached spell list when the engine updates actionbar contents (kit change, memorized-spell change). Replaces the current cache-invalidation via QuickListsChecked / QuickListCountsReset / QuickListNotifyRemoved listeners; new API is the canonical hook.

Scripting-object listener

Opt-in EEex_AIBase_AddScriptingObjectUpdatedListener for cross-script-name tracking. Partial enabler for #19 (clones/summons distinguishable by script-name updates: Project Image clone = COPY, planetar = plangood, Simulacrum = TBD).

Non-goals

• Full clone/summon caster support (that's Support clones/summons as additional casters #19, blocked on this).
• Backwards compatibility with EEex < v1.0.0 (we already committed to v1.0.0 floor in v1.4.0-alpha).

Related

• Support clones/summons as additional casters #19 — clones/summons as additional casters (blocked on this)
• Crash: pressing Stop after reloading a save mid-cast #38 — sprite staleness across save reload (current workaround; UUID would obsolete the workaround)
• New companions joining the party don't inherit the existing preset structure #41 — new-companion preset inheritance (AddLoadedListener already partially addresses; UUID may help track which slot a known character returns to)