fix: scope shellcheck/shfmt as task-level tools; drop from global [tools]

Declaring them in [tools] caused mise to attempt installation on every
task run, blocking all tasks when GitHub's API is rate-limited.
Moving them to #MISE tools={} in the tasks that actually need them means
they're only resolved for shell:check and shell:format.

Author: claude

mise-tasks/shell/check.sh

@@ -1,5 +1,6 @@
 #!/usr/bin/env bash
-#MISE description="Run shellcheck on all shell scripts (scripts/ and mise-tasks/)"
+#MISE description="Run after editing any .sh or mise-tasks/ file"
+#MISE tools={shellcheck="system"}
 
 set -euo pipefail
 

mise-tasks/shell/format.sh

@@ -1,5 +1,6 @@
 #!/usr/bin/env bash
-#MISE description="Format all shell scripts in place with shfmt (scripts/ and mise-tasks/)"
+#MISE description="Run after editing any .sh or mise-tasks/ file"
+#MISE tools={shfmt="system"}
 
 set -euo pipefail
 

mise.toml

@@ -18,8 +18,6 @@ _.path = ["./bin"]
 [tools]
 flutter = "3.38.3"
 node = "22"        # For http_server and Playwright e2e tests
-shellcheck = "0.9.0"
-shfmt = "3.8.0"
 
 [deps.flutter]
 auto = true