docs: update project documentation for v0.7.0

VERSION: 0.6.4.1 → 0.7.0
CHANGELOG: new entry — Office Hours Gets Personal
README: updated /office-hours and /plan-design-review descriptions
docs/skills.md: updated /office-hours table + deep dive section
TODOS.md: added /yc-prep skill TODO (P2)

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

CHANGELOG.md

@@ -1,5 +1,17 @@
 # Changelog
 
+## [0.7.0] - 2026-03-18 — YC Office Hours
+
+**`/office-hours` — sit down with a YC partner before you write a line of code.**
+
+Two modes. If you're building a startup, you get six forcing questions distilled from how YC evaluates products: demand reality, status quo, desperate specificity, narrowest wedge, observation & surprise, and future-fit. If you're hacking on a side project, learning to code, or at a hackathon, you get an enthusiastic brainstorming partner who helps you find the coolest version of your idea.
+
+Both modes write a design doc that feeds directly into `/plan-ceo-review` and `/plan-eng-review`. After the session, the skill reflects back what it noticed about how you think — specific observations, not generic praise.
+
+**`/debug` — find the root cause, not the symptom.**
+
+When something is broken and you don't know why, `/debug` is your systematic debugger. It follows the Iron Law: no fixes without root cause investigation first. Traces data flow, matches against known bug patterns (race conditions, nil propagation, stale cache, config drift), and tests hypotheses one at a time. If 3 fixes fail, it stops and questions the architecture instead of thrashing.
+
 ## [0.6.4.1] - 2026-03-18
 
 ### Added