diff --git a/cli/src/clients/skillhub-client.ts b/cli/src/clients/skillhub-client.ts
index c8ee09ae..1842a178 100644
--- a/cli/src/clients/skillhub-client.ts
+++ b/cli/src/clients/skillhub-client.ts
@@ -179,7 +179,9 @@ export class SkillHubClient {
     } else if (response.status === 404) {
       fallback = kind === 'download' ? 'skill or version not found' : 'resource not found'
     } else if (response.status === 502 || response.status === 503) {
-      fallback = `registry returned ${response.status}`
+      fallback = kind === 'download'
+        ? `download failed with status ${response.status}`
+        : `registry returned ${response.status}`
       exitCode = EXIT.network
     } else {
       fallback = kind === 'download'
diff --git a/cli/test/unit/clients/skillhub-client.test.ts b/cli/test/unit/clients/skillhub-client.test.ts
index 55d0bfb7..187350c1 100644
--- a/cli/test/unit/clients/skillhub-client.test.ts
+++ b/cli/test/unit/clients/skillhub-client.test.ts
@@ -92,6 +92,17 @@ describe('SkillHubClient', () => {
     await err.toHaveProperty('exitCode', EXIT.generic)
   })
 
+  test('download() retains its fallback while classifying 502 as a network error', async () => {
+    const fetchImpl = (async () => new Response(null, { status: 502 })) as unknown as typeof fetch
+    const client = new SkillHubClient('http://registry.test', 'token', fetchImpl)
+
+    await expect(client.download('ns', 'slug')).rejects.toMatchObject({
+      message: 'download failed with status 502',
+      exitCode: EXIT.network,
+      details: { registry: 'http://registry.test' }
+    })
+  })
+
   test('download() throws network error on fetch failure', async () => {
     const fetchImpl = (async () => { throw new TypeError('fetch failed') }) as unknown as typeof fetch
     const client = new SkillHubClient('http://registry.test', 'token', fetchImpl)
@@ -179,6 +190,27 @@ describe('SkillHubClient', () => {
 
   // --- handleJsonResponse() non-2xx classification ---
 
+  test('whoami() preserves public fields and ignores unknown fields on a structured 401', async () => {
+    const fetchImpl = (async () => Response.json({
+      code: 401,
+      msg: 'token has been revoked',
+      requestId: 'req-401',
+      detail: 'internal token state',
+      stack: 'internal stack trace'
+    }, { status: 401 })) as unknown as typeof fetch
+    const client = new SkillHubClient('http://registry.test', 'token', fetchImpl)
+
+    const error = await client.whoami().catch((caught: unknown) => caught)
+    expect(error).toBeInstanceOf(CliError)
+    expect((error as CliError).message).toBe('token has been revoked')
+    expect((error as CliError).exitCode).toBe(EXIT.auth)
+    expect((error as CliError).details).toEqual({
+      registry: 'http://registry.test',
+      requestId: 'req-401',
+      next: 'run `skillhub login`'
+    })
+  })
+
   test('search() preserves a public 403 message and request ID', async () => {
     const fetchImpl = (async () => Response.json({
       code: 403,
@@ -262,6 +294,17 @@ describe('SkillHubClient', () => {
     }
   })
 
+  test('whoami() uses the resource fallback on an unstructured 404', async () => {
+    const fetchImpl = (async () => new Response(null, { status: 404 })) as unknown as typeof fetch
+    const client = new SkillHubClient('http://registry.test', 'token', fetchImpl)
+
+    await expect(client.whoami()).rejects.toMatchObject({
+      message: 'resource not found',
+      exitCode: EXIT.generic,
+      details: { registry: 'http://registry.test' }
+    })
+  })
+
   test('download() preserves a structured 403 message and request ID', async () => {
     const fetchImpl = (async () => Response.json({
       code: 403,
@@ -313,20 +356,63 @@ describe('SkillHubClient', () => {
     })
   })
 
-  test('whoami() throws generic error on 500', async () => {
-    const fetchImpl = (async () => new Response(null, { status: 500 })) as unknown as typeof fetch
+  test('whoami() preserves public fields on a structured 500', async () => {
+    const fetchImpl = (async () => Response.json({
+      code: 500,
+      msg: 'registry operation failed',
+      requestId: 'req-500',
+      detail: 'internal database error'
+    }, { status: 500 })) as unknown as typeof fetch
     const client = new SkillHubClient('http://registry.test', 'token', fetchImpl)
-    const err = expect(client.whoami()).rejects
-    await err.toBeInstanceOf(CliError)
-    await err.toHaveProperty('exitCode', EXIT.generic)
+
+    await expect(client.whoami()).rejects.toMatchObject({
+      message: 'registry operation failed',
+      exitCode: EXIT.generic,
+      details: {
+        registry: 'http://registry.test',
+        requestId: 'req-500'
+      }
+    })
   })
 
-  test('search() throws network error on 502', async () => {
+  test('whoami() does not expose a raw non-JSON 500 body', async () => {
+    const fetchImpl = (async () => new Response('internal stack trace', { status: 500 })) as unknown as typeof fetch
+    const client = new SkillHubClient('http://registry.test', 'token', fetchImpl)
+
+    await expect(client.whoami()).rejects.toMatchObject({
+      message: 'registry returned 500',
+      exitCode: EXIT.generic,
+      details: { registry: 'http://registry.test' }
+    })
+  })
+
+  test('search() preserves public fields and network classification on a structured 502', async () => {
+    const fetchImpl = (async () => Response.json({
+      code: 502,
+      msg: 'registry upstream unavailable',
+      requestId: 'req-502'
+    }, { status: 502 })) as unknown as typeof fetch
+    const client = new SkillHubClient('http://registry.test', 'token', fetchImpl)
+
+    await expect(client.search('test', 20)).rejects.toMatchObject({
+      message: 'registry upstream unavailable',
+      exitCode: EXIT.network,
+      details: {
+        registry: 'http://registry.test',
+        requestId: 'req-502'
+      }
+    })
+  })
+
+  test('search() uses the network fallback on an unstructured 502', async () => {
     const fetchImpl = (async () => new Response(null, { status: 502 })) as unknown as typeof fetch
     const client = new SkillHubClient('http://registry.test', 'token', fetchImpl)
-    const err = expect(client.search('test', 20)).rejects
-    await err.toBeInstanceOf(CliError)
-    await err.toHaveProperty('exitCode', EXIT.network)
+
+    await expect(client.search('test', 20)).rejects.toMatchObject({
+      message: 'registry returned 502',
+      exitCode: EXIT.network,
+      details: { registry: 'http://registry.test' }
+    })
   })
 
   // --- deleteRemote() (P1) ---
diff --git a/docs/skillhub/en/guide/cli.md b/docs/skillhub/en/guide/cli.md
index 49428c9d..4712cbca 100644
--- a/docs/skillhub/en/guide/cli.md
+++ b/docs/skillhub/en/guide/cli.md
@@ -125,15 +125,24 @@ Output format: `namespace/slug  version  summary`
 
 ## Install Skills
 
+Install coordinates accept a bare slug (resolved to `global` by default) and
+three equivalent explicit namespace forms. When an explicit coordinate and
+`--namespace` are both present, they must match.
+
 ```bash
 # Install to auto-detected Agent directory
 skillhub install pdf-parser
 
+# Equivalent namespace coordinates
+skillhub install team/my-skill
+skillhub install @team/my-skill
+skillhub install team--my-skill
+
 # Choose install scope explicitly
 skillhub install pdf-parser --scope user
 skillhub install pdf-parser --scope project --agent codex
 
-# Specify namespace (default: global)
+# Specify a namespace for a bare slug
 skillhub install pdf-parser --namespace myspace
 
 # Specify version
diff --git a/docs/skillhub/guide/cli.md b/docs/skillhub/guide/cli.md
index 4389940a..b4c00da7 100644
--- a/docs/skillhub/guide/cli.md
+++ b/docs/skillhub/guide/cli.md
@@ -125,15 +125,23 @@ skillhub search pdf --json
 
 ## 安装技能
 
+安装坐标支持裸 slug（默认解析到 `global`）和三种等价的显式 namespace
+形式。显式坐标与 `--namespace` 同时出现时，两者必须一致。
+
 ```bash
 # 安装到自动探测的 Agent 目录
 skillhub install pdf-parser
 
+# 等价的 namespace 坐标
+skillhub install team/my-skill
+skillhub install @team/my-skill
+skillhub install team--my-skill
+
 # 显式指定安装范围
 skillhub install pdf-parser --scope user
 skillhub install pdf-parser --scope project --agent codex
 
-# 指定 namespace（默认 global）
+# 为裸 slug 指定 namespace
 skillhub install pdf-parser --namespace myspace
 
 # 指定版本
diff --git a/docs/superpowers/plans/2026-07-28-cli-namespace-errors.md b/docs/superpowers/plans/2026-07-28-cli-namespace-errors.md
index 098e3542..ee71ab89 100644
--- a/docs/superpowers/plans/2026-07-28-cli-namespace-errors.md
+++ b/docs/superpowers/plans/2026-07-28-cli-namespace-errors.md
@@ -16,14 +16,14 @@ revalidation did not recreate historical RED states; it reran the current
 GREEN gates with the repository-pinned Bun 1.3.13:
 
 - Focused namespace/error/help regression: 142 tests passed.
-- Complete CLI regression: 373 tests passed with
-  `bun test --max-concurrency=1` (peak RSS 170224 KiB).
+- Complete CLI regression: 378 tests passed with
+  `bun test --max-concurrency=1` (peak RSS 152128 KiB).
 - Typecheck, lint, and build passed.
 - The packed `@astron-team/skillhub@0.1.9` artifact contained `dist/index.js`,
   `README.md`, `CHANGELOG.md`, `LICENSE`, and `package.json`.
-- Packed Node artifact smoke passed for `version`, `help install`, and
-  `remove --help`; the install help listed all three namespaced coordinate
-  forms.
+- Packed Node artifact smoke passed for `version`, `help install`, all three
+  namespaced coordinate forms, coordinate/`--namespace` conflict handling, and
+  structured 403 message/request-ID rendering.
 - The Chinese and English VitePress documentation build passed.
 
 ---