feat(ux): add Apple's 10 Essential Design Principles (WWDC 2017)

[fazalrshah]

What & why

Adds Apple's ten Essential Design Principles from WWDC 2017 — Session 802 "Essential Design Principles" (Mike Stern) to the UX knowledge base. These are timeless, human-centered product principles that complement the skill's existing tactical rules — they describe the why (the experience you're designing for) where the current rule categories describe the measurable how.

The talk's framing — design to meet four human needs: safety, meaning, achievement, and beauty — is captured as the section intro.

Changes

Data (the core contribution)

• src/ui-ux-pro-max/data/ux-guidelines.csv — +10 rows under a new Apple Design Principles category, each with description / Do / Don't / good + bad examples / severity:
  Wayfinding · Feedback · Visibility · Consistency · Mental Models · Proximity & Grouping · Mapping · Affordances · Progressive Disclosure · Symmetry & Balance
• These are picked up by search.py and surface via --domain ux and the --design-system flow.

Guidance

• src/ui-ux-pro-max/templates/base/quick-reference.md + .claude/skills/ui-ux-pro-max/SKILL.md — a new "Foundational Design Principles" section placed just above the Rule Categories table, so the principles are read at the concept stage.

Housekeeping

• Bumped the advertised guideline count 99 → 109 in skill.json, README.md, and the platform template descriptions.
• Synced src/ → cli/assets/ per the contributor guide in the README.

Verification

• CSV parses cleanly: 109 rows, no gaps, CRLF preserved (append-only diff).
• All changed JSON validated.
• search.py "apple design principles" --domain ux returns the new rows.
• cli/assets kept byte-in-sync with src/ for the touched files.

Notes

• CSV append preserves the file's existing CRLF line endings (the diff is purely additive).
• Principle definitions are sourced directly from the session; phrasing condensed for the dataset format.