feat: support cloudflare R2 natively

[dheerapat]

Natively support Cloudflare's R2

---

Summary by cubic

Add native Cloudflare R2 support to DuckLake and quack by configuring DuckDB secrets via env vars. Docs add r2://, examples/r2-ducklake, and support remote PostgreSQL/MySQL catalogs; quack UI now runs CREATE SECRET, and we only set the active database when the client is DuckLake.

• Migration
  • Replace provider-specific env vars with LEA_DUCKLAKE_SECRET and LEA_QUACK_DUCKLAKE_SECRET (the body of DuckDB CREATE SECRET).

^{Written for commit 951e93f. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 1 file

[MaxHalford]

I would assume R2 is compatible with S3, so we shouldn't need specific env vars. Let me give it a try.

[dheerapat]

@MaxHalford duckdb have specific secret type r2 to work with cloudflare so it very easy to connect via this specific secret type

[cubic-dev-ai]

3 issues found across 7 files (changes from recent commits).

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="examples/quack/README.md">

<violation number="1" location="examples/quack/README.md:85">
P2: README shell example uses an unquoted env value with spaces, causing command parsing errors when copy-pasted.</violation>
</file>

<file name="examples/r2-ducklake/README.md">

<violation number="1" location="examples/r2-ducklake/README.md:28">
P2: README quickstart path is broken: `--scripts jaffle_shop/scripts` does not match the symlink target and repository layout, causing a non-existent scripts directory.</violation>
</file>

<file name="README.md">

<violation number="1" location="README.md:162">
P2: README shell snippets use unquoted env values with spaces, causing copy-paste commands to fail in POSIX shells.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review, or fix all with cubic.}

[MaxHalford]

Alright @dheerapat I've made some changes in order to support any kind of secret, not just R2 secrets. Now you can do this:

LEA_USERNAME=max
LEA_WAREHOUSE=ducklake
LEA_DUCKLAKE_CATALOG_DATABASE=metadata.ducklake
LEA_DUCKLAKE_DATA_PATH=r2://lea-demo
LEA_DUCKLAKE_SECRET=TYPE r2, KEY_ID '<key_id>', SECRET '<secret>', ACCOUNT_ID '<account_id>'