[side-quest] Add Step 22 resilience reference side quest and streamline main path

[Copilot]

Step 22 had grown into a mixed path: the core /agentic-workflows flow plus detailed manual-reference content. This change splits the deep reference material into an optional side quest and keeps the main step concise while preserving seamless learner routing.

• Main step routing (workshop/22-error-handling-and-resilience.md)

  • Added an optional [!TIP] callout to a new side quest for manual/deep-dive learners.
  • Condensed the three resilience technique sections into short operational summaries:
    • defensive brief behavior for empty data
    • top-level timeout-minutes
    • safe-output fallback messaging

• New side quest (workshop/side-quest-22-01-resilience-reference.md)

  • Added a focused reference page for the three resilience techniques with:
    • copy-ready syntax blocks
    • predict-and-try prompts
    • GHES/GHEC timeout policy note
    • return link back to Step 22
    • checkpoint section

• Curriculum index update (workshop/README.md)

  • Added “Resilience Techniques Reference” to Optional Side Quests with explicit branch point from Step 22.

> [!TIP]
> Optional side quest: if you want full syntax examples, predict-and-try checks, and enterprise timeout notes before you edit manually, use [Side Quest: Resilience Techniques Reference](side-quest-22-01-resilience-reference.md), then return here to continue.

• Fixes [side-quest] feat: side quest 22-01 — Resilience Techniques Reference #2451

[pelikhan]

@copilot apply guidelines

[Copilot]

@copilot apply guidelines

Applied guideline alignment in commit f4fc1b9: added an optional gh aw compile --watch TIP to the new Step 22 side quest so compile guidance matches repository standards while keeping the main path unchanged.