fix: correct v2.1.39/v2.1.41 feature attributions + add claude auth CLI docs

3 features were incorrectly attributed to v2.1.39 instead of v2.1.41
(guard nested sessions, OTel speed attribute, Agent Teams model fix).
Verified against official CHANGELOG. Also adds claude auth login/status/logout
to the ultimate guide maintenance commands table.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

guide/claude-code-releases.md

@@ -35,10 +35,18 @@ tags: [reference, release]
 
 ### v2.1.41 (2026-02-13)
 
+- **New**: Guard against launching Claude Code inside another Claude Code session
 - **New**: `claude auth login`, `claude auth status`, `claude auth logout` CLI subcommands
 - **New**: Windows ARM64 (win32-arm64) native binary support
+- Added `speed` attribute to OTel events and trace spans for fast mode visibility
 - **Improved**: `/rename` auto-generates session name from conversation context when called without arguments
 - Improved narrow terminal layout for prompt footer
+- Fixed: Agent Teams using wrong model identifier for Bedrock, Vertex, and Foundry customers
+- Fixed: Crash when MCP tools return image content during streaming
+- Fixed: `/resume` session previews showing raw XML tags instead of readable command names
+- Fixed: Opus 4.6 launch announcement showing for Bedrock/Vertex/Foundry users
+- Fixed: Hook blocking errors (exit code 2) not showing stderr to the user
+- Fixed: Structured-outputs beta header sent unconditionally on Vertex/Bedrock
 - Fixed: File resolution for @-mentions with anchor fragments (e.g., `@README.md#installation`)
 - Fixed: FileReadTool blocking on FIFOs, `/dev/stdin`, and large files
 - Fixed: Background task notifications not delivered in streaming Agent SDK mode
@@ -46,20 +54,15 @@ tags: [reference, release]
 - Fixed: Stale permission rules not clearing when settings change on disk
 - Fixed: Permission wait time included in subagent elapsed time display
 - Fixed: Proactive ticks firing while in plan mode
-
-### v2.1.39 (2026-02-11)
-
-- **New**: Guard against launching Claude Code inside another Claude Code session
-- Added `speed` attribute to OTel events and trace spans for fast mode visibility
-- Fixed: Agent Teams using wrong model identifier for Bedrock, Vertex, and Foundry customers
-- Fixed: Crash when MCP tools return image content during streaming
-- Fixed: `/resume` session previews showing raw XML tags instead of readable command names
-- Fixed: Opus 4.6 launch announcement showing for Bedrock/Vertex/Foundry users
-- Fixed: Hook blocking errors (exit code 2) not showing stderr to the user
-- Fixed: Structured-outputs beta header sent unconditionally on Vertex/Bedrock
 - Improved: Model error messages for Bedrock/Vertex/Foundry with fallback suggestions
+
+### v2.1.39 (2026-02-10)
+
 - Improved: Terminal rendering performance
-- Multiple stability fixes (fatal errors, process hanging, character loss at screen boundary)
+- Fixed: Fatal errors being swallowed instead of displayed
+- Fixed: Process hanging after session close
+- Fixed: Character loss at terminal screen boundary
+- Fixed: Blank lines in verbose transcript view
 
 ### v2.1.38 (2026-02-10)
 

guide/ultimate-guide.md

@@ -260,6 +260,9 @@ claude doctor
 | `claude update` | Check and install updates | Weekly or when encountering issues |
 | `claude doctor` | Verify auto-updater health | After system changes or if updates fail |
 | `claude --version` | Display current version | Before reporting bugs |
+| `claude auth login` | Authenticate from the command line | CI/CD, devcontainers, scripted setups |
+| `claude auth status` | Check current authentication state | Verify which account/method is active |
+| `claude auth logout` | Clear stored credentials | Shared machines, security cleanup |
 
 **Update frequency recommendations:**
 - **Weekly**: Check for updates during normal development