chore(crabbox): default remote proof to Blacksmith Testbox

The azure coordinator has been timing out (10m, no lease) while delegated
Blacksmith Testbox leases in about a minute. Make blacksmith-testbox the
.crabbox.yaml default, keep --provider aws/azure for direct VM proof, and
refresh the crabbox/openclaw-testing skill text that still claimed an AWS
default. Formatting proof: sibling-checkout oxfmt --check passed (hook needs
node_modules this worktree lacks). Testbox proof: tbx_01kwp8h31773z2vphbcae1syzr
(node --version, exit 0, 1m07s) via
https://github.com/openclaw/openclaw/actions/runs/28702438266

.agents/skills/crabbox/SKILL.md

@@ -43,11 +43,11 @@ pnpm crabbox:run -- --help | sed -n '1,120p'
 
 - OpenClaw scripts prefer `../crabbox/bin/crabbox` when present. The user PATH
   shim can be stale.
-- Check `.crabbox.yaml` for direct-provider defaults. Omitting `--provider`
-  means brokered AWS for normal Linux/macOS paths; the wrapper selects Azure
-  for unqualified Windows/WSL2 runs when the local Crabbox binary advertises
-  Azure.
-- The brokered AWS default is a Linux developer image in `eu-west-1`; the repo
+- Check `.crabbox.yaml` for the provider default. Omitting `--provider`
+  means Blacksmith Testbox through Crabbox for normal Linux paths; the wrapper
+  selects Azure for unqualified Windows/WSL2 runs when the local Crabbox
+  binary advertises Azure. Pass `--provider aws` for direct brokered AWS runs.
+- The brokered AWS image is a Linux developer image in `eu-west-1`; the repo
   config pins hot `eu-west-1a/b/c` placement so Fast Snapshot Restore can apply.
   If warmup drifts well past the minute-scale path, verify image promotion,
   region/AZ placement, and FSR state before blaming OpenClaw.

.agents/skills/openclaw-testing/SKILL.md

@@ -28,7 +28,8 @@ Prove the touched surface first. Do not reflexively run the whole suite.
      For maintainer heavy `pnpm` gates, that is usually delegated Blacksmith
      Testbox through Crabbox, e.g. `node scripts/crabbox-wrapper.mjs run
 --provider blacksmith-testbox ... -- env OPENCLAW_CHECK_CHANGED_REMOTE_CHILD=1 OPENCLAW_CHANGED_LANES_RAW_SYNC=1 corepack pnpm check:changed`. For direct AWS
-     Crabbox proof, omit `--provider` and let `.crabbox.yaml` choose AWS.
+     Crabbox proof, pass `--provider aws`; omitting `--provider` follows the
+     `.crabbox.yaml` default (Blacksmith Testbox).
    - workflow-only: `git diff --check`, workflow syntax/lint (`actionlint` when available)
    - docs-only: `pnpm docs:list`, docs formatter/lint only if docs tooling changed or requested
 2. Reproduce narrowly before fixing.

.crabbox.yaml

@@ -1,14 +1,17 @@
 profile: openclaw-check
-# Default OpenClaw runner spend to the Azure-backed Crabbox account.
-# Use `--provider aws` only for AWS-specific runner proof.
-provider: azure
+# Default OpenClaw remote proof to Blacksmith Testbox through Crabbox: the
+# delegated CI environment owns checkout/hydration and leases reliably.
+# Use `--provider aws` for direct AWS runner proof; `--provider azure` spends
+# the Azure-backed credit account (its coordinator has stalled under load).
+provider: blacksmith-testbox
 class: standard
 capacity:
+  # Class/capacity apply only to direct VM providers (`--provider aws|azure`);
+  # delegated Blacksmith runs ignore them. Keep explicit on-demand capacity
+  # instead of low-priority spot, whose regional quota is too small for broad
+  # maintainer proof or parallel Crabbox lanes.
   market: on-demand
   strategy: most-available
-  # The Azure-backed billing account carries the OpenClaw runner credits; use
-  # explicit on-demand capacity instead of low-priority spot, whose regional
-  # quota is too small for broad maintainer proof or parallel Crabbox lanes.
   hints: true
 actions:
   workflow: .github/workflows/crabbox-hydrate.yml