Mark the DD track and AD102/AD103 live on the hub

[vproHacks]

Six courses that courses.json still lists as planned are now published and reachable:

id	title	live
ad102	Linear Circuits & Fabrication	https://uoftasic.com/ad102/
ad103	Nonlinear Circuits	https://uoftasic.com/ad103/
dd101	Intro to Digital Logic	https://uoftasic.com/dd101/
dd102	Digital Logic & FPGAs	https://uoftasic.com/dd102/
dd103	RTL on FPGAs & ASICs	https://uoftasic.com/dd103/
dd104	Pre-Silicon Verification	https://uoftasic.com/dd104/

Each is its own repo under uoftasic with Pages from /docs, matching ic101 and ad101. Verified anonymously — each returns 200 and clones without credentials.

Deliberately left for a human to merge

The repos had to be published for the courses to function at all: the org is on the free plan, so GitHub Pages cannot serve a private repo, and every lab package, checker and worksheet is fetched over https://github.com/uoftasic/<id>/…. Student testing found all eight personas quitting at the first such link while the repos were private.

But published and announced are different decisions. Merging this makes the courses discoverable from the hub. They are drafts: heavily verified — every command run, every number measured, two rounds of eight-persona student testing already fixed — but not yet reviewed by a human on the team.

So this PR is opened, not merged. Merge it when you are ready for students to find them.

[vproHacks]

Pushed two fixes to this branch. Still not merging — announcing the courses is your call.

1. The PR did not change what visitors see. It flipped six courses to live in data/courses.json, but index.html — the file Pages actually serves — is generated from that JSON by scripts/build.py, and was never rebuilt. Merging as-is would have marked the courses live in data while the page still showed them under Planned modules with nothing to click, which is the exact problem this PR exists to fix. Rebuilt with build.py rather than hand-edited.

2. AD104 was still planned. It is published and serves 200.

The hub now links all nine live courses:

Linked as live	IC101, AD101, AD102, AD103, AD104, DD101, DD102, DD103, DD104
Left on the roadmap	AD201, AD202, DD201, DD202 — the four not started

Every generated link verified:

https://uoftasic.com/ic101/   200      https://uoftasic.com/dd101/   200
https://uoftasic.com/ad101/   200      https://uoftasic.com/dd102/   200
https://uoftasic.com/ad102/   200      https://uoftasic.com/dd103/   200
https://uoftasic.com/ad103/   200      https://uoftasic.com/dd104/   200
https://uoftasic.com/ad104/   200