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/llm/llm-retry/tests/transport-recovery.spec.ts

@@ -93,7 +93,7 @@ describe('bounded retry through the real DeepSeek HTTP/SSE adapter', () => {
     const port = await unusedPort()
     context = await harness(`http://127.0.0.1:${port}`, { initialDelayMs: 100 })
     const agent = context.agentLoop.create(SessionId('wire-refused'), {
-      provider: 'deepseek',
+      provider: 'deepseek-official',
       model: 'mock-model',
     })
     let recoveryServer: Promise<MockLlmServer> | undefined
@@ -128,7 +128,7 @@ describe('bounded retry through the real DeepSeek HTTP/SSE adapter', () => {
     })
     context = await harness(server.baseURL)
     const agent = context.agentLoop.create(SessionId(`wire-${behavior}`), {
-      provider: 'deepseek',
+      provider: 'deepseek-official',
       model: 'mock-model',
     })
 
@@ -154,7 +154,7 @@ describe('bounded retry through the real DeepSeek HTTP/SSE adapter', () => {
     })
     context = await harness(server.baseURL)
     const agent = context.agentLoop.create(SessionId('wire-empty'), {
-      provider: 'deepseek',
+      provider: 'deepseek-official',
       model: 'mock-model',
     })
 
@@ -182,7 +182,7 @@ describe('bounded retry through the real DeepSeek HTTP/SSE adapter', () => {
     })
     context = await harness(server.baseURL)
     const agent = context.agentLoop.create(SessionId('wire-partial-eof'), {
-      provider: 'deepseek',
+      provider: 'deepseek-official',
       model: 'mock-model',
     })
 
@@ -209,7 +209,7 @@ describe('bounded retry through the real DeepSeek HTTP/SSE adapter', () => {
     // the stalled attempt and the mock server's immediate successful response.
     context = await harness(server.baseURL, { streamIdleTimeoutMs: 1_000 })
     const agent = context.agentLoop.create(SessionId('wire-stall'), {
-      provider: 'deepseek',
+      provider: 'deepseek-official',
       model: 'mock-model',
     })
 
@@ -227,7 +227,7 @@ describe('bounded retry through the real DeepSeek HTTP/SSE adapter', () => {
     })
     context = await harness(server.baseURL)
     const agent = context.agentLoop.create(SessionId('wire-exhausted'), {
-      provider: 'deepseek',
+      provider: 'deepseek-official',
       model: 'mock-model',
     })