feat: make examples cumulative with carry-forward chain and capstone

Add three new sections to all 14 examples:
- "Carry Forward": what output feeds into later examples (01-10)
- "The Cumulative Path": alternative prompt building on previous output (02-10)
- "Now Try It Yourself": personalized template with transferable pattern (all)
- "Building On" callout connecting back to previous examples (02-10)

Add Example 14: Build Your Personal Agent - capstone that guides reader
through writing their own CLAUDE.md, creating a personal skill, connecting
a messaging channel, setting up automation, and testing end-to-end.

Update README with cumulative path diagram, two usage modes, and example 14.
Update GETTING-STARTED.md with cross-references to relevant examples.

17 files changed, 703+ lines added. The examples now form a coherent
learning path from "see what it can do" to "build your own agent."

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

examples/13-auto-mode/prompt.md

@@ -81,3 +81,29 @@ Different philosophy:
 Both have trade-offs. Sandboxes catch unknown threats. Classifiers
 prevent the action from happening at all but may miss novel attacks
 (5.7% false negative rate).
+
+---
+
+## Now Try It Yourself
+
+Auto Mode works best for well-defined, bounded tasks. Try it on something safe first:
+
+```
+[With Auto Mode enabled]
+Read all markdown files in this project. Create a table of contents
+in pipeline-output/index.md listing every file with a one-line
+description. Verify the file count matches.
+```
+
+**The pattern you just learned:** Auto Mode removes the permission prompts. Use it when you trust the task scope and want Claude to work without interruption. Start with read-heavy, write-light tasks and expand as you build confidence.
+
+When to use Auto Mode:
+- Research tasks where you trust the search and write scope
+- File organization within a known project
+- Running a tested pipeline end-to-end without babysitting
+- Batch processing files with a predictable pattern
+
+When NOT to use Auto Mode:
+- First time running an untested pipeline
+- Tasks that touch production systems or external APIs
+- Anything involving credentials, payments, or irreversible actions