refactor(llm-deepseek)!: rename the provider route to deepseek-official

The native adapter's route was named deepseek, colliding with pi-ai's
catalog provider of the same name, so the two DeepSeek paths could never
be mounted side by side. The web settings page needs both configurable at
once. Compositions, fixtures, goldens, scaffolding defaults, and docs all
move together (pre-release, no shim); TUI/session-query-spill/
missing-credential goldens re-recorded through their keyless refresh
modes because provider-name length shifts box padding and spill
truncation points.

packages/sdk/sdk-client/README.md

@@ -13,7 +13,7 @@ import { DeepSeekHarness } from '@deepseek-ai/dsh-sdk-client'
 
 await using harness = new DeepSeekHarness({
   launch: { command: 'node', args: ['lib/bin.js', 'cordis.yml'] },
-  provider: 'deepseek',
+  provider: 'deepseek-official',
   model: 'deepseek-v4-flash',
   maxTokens: 49_152,
 })

packages/sdk/sdk-client/README.zh.md

@@ -13,7 +13,7 @@ import { DeepSeekHarness } from '@deepseek-ai/dsh-sdk-client'
 
 await using harness = new DeepSeekHarness({
   launch: { command: 'node', args: ['lib/bin.js', 'cordis.yml'] },
-  provider: 'deepseek',
+  provider: 'deepseek-official',
   model: 'deepseek-v4-flash',
   maxTokens: 49_152,
 })

packages/sdk/sdk-client/src/api.ts

@@ -37,7 +37,7 @@ export class DeepSeekHarness implements AsyncDisposable {
     // process's cwd, but the wire cwd is resolved again inside the child — a
     // relative value would double-resolve (e.g. `worker` → `worker/worker`).
     this.cwd = resolve(options.cwd ?? options.launch.cwd ?? process.cwd())
-    this.provider = options.provider ?? 'deepseek'
+    this.provider = options.provider ?? 'deepseek-official'
     this.model = options.model ?? 'deepseek-v4-flash'
     this.maxTokens = options.maxTokens
   }

packages/sdk/sdk-client/src/types.ts

@@ -51,7 +51,7 @@ export interface DeepSeekHarnessOptions {
   launch: HarnessClientOptions
   /** Workspace cwd recorded on every SDK-created session (default: the launch cwd, else `process.cwd()`). */
   cwd?: string
-  /** Provider route for SDK-created agents (default `deepseek`). */
+  /** Provider route for SDK-created agents (default `deepseek-official`). */
   provider?: string
   /** Model for SDK-created agents (default `deepseek-v4-flash`). */
   model?: string