feat(tooling): enforce noUncheckedIndexedAccess in the extensions lane (NUIA phase 4) (#105132)

* fix(extensions): make indexed access explicit across channel plugins

Transport-payload-safe burn-down: malformed Telegram/Discord/QQ/LINE
and sibling channel input keeps existing skip paths; no synthesized
fields, no new throws in delivery loops. Zalo escape sentinels preserve
literal matches instead of undefined replacements.

* fix(extensions): make indexed access explicit across provider and memory plugins

Stream and model iteration, tool-block guards, capture guards, and
sparse accumulators; singleton model reads carry named invariants.

* fix(extensions): make indexed access explicit across tooling plugins, flip the extensions lane

Remaining plugins (oc-path, qa-lab, browser, logbook, and siblings) plus
the tsconfig.extensions.json flag flip. Cleanup: logbook sampleFrames
NaN index at max=1, QA retry clamp at non-positive attempts, dead Canvas
probe and OpenShell no-op slice removed, twitch test setup leak excluded
from the prod lane.

* refactor(plugin-sdk): expose expectDefined via a focused SDK subpath

Extensions imported @openclaw/normalization-core directly, crossing the
external-plugin packaging boundary (it only worked because the runtime
builder bundles undeclared workspace helpers). expect-runtime joins the
canonical entrypoints JSON, generated exports, API baseline, docs, and
subpath contract test; all 78 extension imports now use the SDK seam.
Two scanner-shaped locals renamed for review-bundle hygiene.

* chore(plugin-sdk): raise surface budgets for the expect-runtime subpath

One new entrypoint with one callable export, added intentionally as the
packaging-honest seam for extension invariant helpers.

scripts/lib/plugin-sdk-entrypoints.json

@@ -67,6 +67,7 @@
   "delivery-queue-runtime",
   "file-access-runtime",
   "heartbeat-runtime",
+  "expect-runtime",
   "number-runtime",
   "secure-random-runtime",
   "system-event-runtime",

scripts/plugin-sdk-surface-report.mjs

@@ -194,17 +194,17 @@ export function readPluginSdkSurfaceBudgets(env = process.env) {
   const budgets = {
     publicEntrypoints: readPluginSdkSurfaceBudgetEnv(
       "OPENCLAW_PLUGIN_SDK_MAX_PUBLIC_ENTRYPOINTS",
-      326,
+      327,
       env,
     ),
     publicExports: readPluginSdkSurfaceBudgetEnv(
       "OPENCLAW_PLUGIN_SDK_MAX_PUBLIC_EXPORTS",
-      10623,
+      10624,
       env,
     ),
     publicFunctionExports: readPluginSdkSurfaceBudgetEnv(
       "OPENCLAW_PLUGIN_SDK_MAX_PUBLIC_FUNCTION_EXPORTS",
-      5348,
+      5349,
       env,
     ),
     publicDeprecatedExports: readPluginSdkSurfaceBudgetEnv(