docs: add Session Teleportation documentation (v3.9.4)

- Add Section 9.16 Session Teleportation in ultimate-guide.md (~105 lines)
  - Evolution timeline (2.0.24 → 2.1.0)
  - Commands: %, &, --teleport, /teleport, /tasks, /remote-env, Ctrl+B
  - Prerequisites, limitations, environment support matrix
- Update cheatsheet.md with new commands and shortcuts
- Update reference.yaml with new entries and line numbers
- Add cowork.md (collaboration guidance)
- Bump version to 3.9.4

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

machine-readable/reference.yaml

@@ -3,7 +3,7 @@
 # Source: guide/ultimate-guide.md
 # Purpose: Condensed index for LLMs to quickly answer user questions about Claude Code
 
-version: "3.9.1"
+version: "3.9.4"
 updated: "2026-01"
 
 # ════════════════════════════════════════════════════════════════
@@ -91,18 +91,28 @@ deep_dive:
   git_best_practices: 8190
   subscription_limits: 1750
   cost_optimization: 8047
-  commands_table: 9267
-  shortcuts_table: 9300
-  troubleshooting: 9426
-  cheatsheet: 9801
-  daily_workflow: 9877
-  # AI Ecosystem (Section 11, ~line 10156)
-  ai_ecosystem: 10156
-  ai_ecosystem_complementarity: 10170
-  ai_ecosystem_tool_matrix: 10196
-  ai_ecosystem_workflows: 10221
-  ai_ecosystem_integration: 10347
+  session_teleportation: 9223
+  commands_table: 9399
+  shortcuts_table: 9432
+  troubleshooting: 9558
+  cheatsheet: 9933
+  daily_workflow: 10009
+  # AI Ecosystem (Section 11, ~line 10271)
+  ai_ecosystem: 10271
+  ai_ecosystem_complementarity: 10285
+  ai_ecosystem_tool_matrix: 10311
+  ai_ecosystem_workflows: 10336
+  ai_ecosystem_integration: 10462
   ai_ecosystem_detailed: "guide/ai-ecosystem.md"
+  ai_ecosystem_alternative_providers: "guide/ai-ecosystem.md:902"
+  # Cowork documentation
+  cowork_full: "guide/cowork.md"
+  cowork_section: "guide/ai-ecosystem.md:701"
+  cowork_comparison: "guide/cowork.md:115"
+  cowork_use_cases: "guide/cowork.md:140"
+  cowork_security: "guide/cowork.md:200"
+  cowork_workflows: "guide/cowork.md:270"
+  cowork_ultimate_guide: 10521
 
 # ════════════════════════════════════════════════════════════════
 # DECISION TREE (most important - en premier)
@@ -156,6 +166,9 @@ commands:
   /model: "switch: sonnet|opus|opusplan"
   /mcp: "show MCP server status"
   /context: "detailed token breakdown"
+  /teleport: "bring web session to local CLI"
+  /tasks: "monitor background tasks"
+  /remote-env: "configure cloud environment"
 
 # ════════════════════════════════════════════════════════════════
 # SHORTCUTS - see deep_dive.shortcuts_table
@@ -165,6 +178,7 @@ shortcuts:
   Esc×2: "rewind/undo"
   Ctrl+C: "interrupt"
   Ctrl+R: "retry"
+  Ctrl+B: "background all tasks"
   "@file": "reference file"
   "!cmd": "shell command"
 
@@ -174,6 +188,7 @@ shortcuts:
 cli:
   "-c": "continue last session"
   "-r <id>": "resume specific session"
+  "--teleport": "bring web session to local CLI"
   "-p": "non-interactive (pipe mode)"
   "--model X": "select model"
   "--dangerously-skip-permissions": "auto-accept ALL (danger)"
@@ -345,7 +360,7 @@ rules:
 ecosystem:
   this_guide:
     focus: "Education - Learn & master"
-    unique: ["architecture docs", "TDD/SDD methodologies", "217-question quiz", "YAML index"]
+    unique: ["architecture docs", "TDD/SDD methodologies", "227-question quiz", "YAML index"]
   complementary:
     claude_code_templates:
       url: "github.com/davila7/claude-code-templates"
@@ -358,6 +373,11 @@ ecosystem:
       url: "github.com/wesammustafa/Claude-Code-Everything"
       focus: "Visual walkthrough - Screenshots, BMAD method"
   install_templates: "scripts/install-templates.sh"
+  cowork:
+    description: "Claude Code for non-developers (desktop app)"
+    status: "Research preview - Max/macOS only (Jan 2026)"
+    blog: "https://claude.com/blog/cowork-research-preview"
+    guide: "guide/cowork.md"
 
 # ════════════════════════════════════════════════════════════════
 # ONBOARDING MATRIX - Maps user profile → content sections