feat: split data update from site build; publish via Cloudflare Pages

The updater fetched GitHub metadata and rendered the dashboard payload in
a single step, so anything that published the site needed a GITHUB_TOKEN.
Cloudflare Pages builds from a Git webhook and has no business holding
one.

Split the tool into three modes. The default update step still fetches
GitHub and now records every API-sourced field in data/metadata.json,
which is committed alongside README.md and data/history.jsonl. The new
-build mode joins that snapshot with data/agents.yml and
data/history.jsonl to render dist/ with no network access and no token;
-check is unchanged.

Supporting changes:

- computeDeltaAt anchors the delta windows to when the data was fetched
  rather than the wall clock, so a redeploy days later reproduces the
  same Δ7d instead of sliding the window past its slack allowance.
- writeSiteData takes updatedAt explicitly for the same reason: the
  timestamp labels data freshness, not build time.
- sortStats is extracted from fetchStats so the build step re-ranks
  identically from committed metadata.
- An agents.yml entry with no metadata yet is omitted with a warning
  instead of failing the build, which would otherwise block every deploy
  between merging a new entry and the next nightly run.
- update.yml drops the GitHub Pages deploy steps and commits
  data/metadata.json; ci.yml runs `go run . -build` so a build that would
  break on deploy breaks in CI first.
- site/_headers stops the edge serving a stale data.json after a refresh.
- docs/DEPLOY.md covers the Cloudflare setup, including the one-time
  bootstrap of data/metadata.json that the build depends on.

Also carries the in-progress curation work already in the tree: the
module rename to awesome-ai-dev-tools, retagged entries, and removal of
the archived Roo-Code, void, continue and suna entries.

plans/reports/research-260911-1328-agents-refresh.md

@@ -1,6 +1,6 @@
-# Research Report: awesome-coding-agents list refresh (additions + stale cleanup)
+# Research Report: awesome-ai-dev-tools list refresh (additions + stale cleanup)
 
-**Conducted:** 2026-09-11 13:28 (+07) · **Repo:** `tiennm99/awesome-coding-agents` · **Tracked now:** 29
+**Conducted:** 2026-09-11 13:28 (+07) · **Repo:** `tiennm99/awesome-ai-dev-tools` · **Tracked now:** 29
 
 ## Executive Summary