Progress for Azure/typespec-azure#4564

Summary

Makes main.tsp import ./client.tsp for deploymentStacks, policy, and search, now that the autorest emitter honors the @scope TCGC decorator (Azure/typespec-azure#4565, shipped in @azure-tools/typespec-autorest@0.69.1, upgraded in #44014).

These services' client.tsp declare language-restructured operations via @@scope(...). Previously the autorest emitter ignored @scope and emitted all of them, so main.tsp could not import client.tsp without injecting phantom operations into the swagger (~1300 lines for deploymentStacks, ~840 for policy). With @scope now honored, the scoped-out operations are correctly omitted.

search

search needed a few extra customizations to reach byte-identical output:

• Added @@scope(..., "!autorest") to the 24 client-only customization operations so the autorest emitter no longer emits them (some had body: void, which previously caused emit failures).
• Scoped the three SearchResourceEncryptionKey @@clientName renames (keyName/keyVersion/vaultUri) to "!autorest" so they don't leak x-ms-client-name into the swagger.
• Moved the three client-only models (search-management-request-options, AccessRulePropertiesSubscriptionsItem, SearchServiceNetworkSecurityPerimeterInboundRuleSubscription) into a dedicated top-level SearchClientCustomizations namespace (new client-customizations.tsp). The autorest emitter enumerates all named models in the service namespace when omit-unreachable-types is off; relocating these client-only types keeps them out of the swagger while preserving their names for SDK generation.

Verification

For all three services, regenerating with the autorest emitter produces swagger byte-identical to what is checked in, across all API versions, and compiles cleanly under --warn-as-error. Only .tsp files change; no generated swagger changes.

Related

Part of the effort to make main.tsp the single TypeSpec compilation entry point. Companion PR #44009 covers services that work with omit-unreachable-types.