fix(templateengine+centralui): resolve follow-ups #3 (derived-template collisions) and #7 (sandbox batch/wait surface)

#3 — CollisionDetector counted a derived template's IsInherited placeholder
rows as a distinct origin from the parent members the inheritance walk
re-adds, reporting a spurious "Naming collision" for every inherited row and
blocking any attribute/composition add to a derived template. CollectDirectMembers
now skips IsInherited rows on the direct-template and inherited-parent walks;
it keeps them for the composed-module walk, where placeholders are the sole
representation of a derived module's inherited members (that walk does not
climb the composed template's parent chain).

#7 — SandboxAttributeAccessor (Central UI Test-Run host) omitted
WriteBatchAndWaitAsync / WaitAsync / WaitForAsync, so the editor false-flagged
valid instance scripts with CS1061 even though `template validate` and the
deploy gate accept them. Added the five overloads mirroring the runtime
AttributeAccessor; they throw a labelled ScriptSandboxException if run in
Test Run (the central sandbox has no device-batch / event-waiter transport).

Tests: +3 CollisionDetector unit + 1 end-to-end TemplateService (derived add
now succeeds); +2 ScriptAnalysisService diagnose-clean. Each new test verified
to fail without its fix with the exact user-facing symptom. Full suites green
(TemplateEngine.Tests 438, CentralUI.Tests 866).

Docs: Component-TemplateEngine.md (inherited-placeholder collision rule),
Component-ScriptAnalysis.md (third sandbox surface + its compile-clean guard),
known-issues tracker #3/#7 marked resolved and the minor note promoted to #8.

docs/requirements/Component-TemplateEngine.md

@@ -124,6 +124,8 @@ When a template composes two or more feature modules, the system must check for
 
 If any composed module introduces a name that already exists (from another composed module or from the composing template itself), this is a **design-time error**. The template cannot be saved until the conflict is resolved. Collision detection is performed recursively for nested module compositions.
 
+A derived template stores `IsInherited` placeholder rows that mirror the members it inherits from its parent chain. These placeholders are **excluded** from collision detection on the template's own member set and on the inherited-parent walk — the inheritance walk already re-adds those members under the parent's origin, so counting the placeholder copies as well would report a spurious self-collision against the very member they mirror. (Placeholders are only counted when a composed module is itself a derived template, because the composed-module walk does not climb that module's parent chain and the placeholders are then the sole representation of its inherited members.) Without this exclusion there is no supported way to add an attribute, alarm, script, or composition to a derived template — every add is blocked by false collisions on the pre-existing inherited rows.
+
 ## Flattening Process
 
 When an instance is deployed, the Template Engine resolves the full configuration: