Add explicit Taskfile usage guidance to CLAUDE.md (#4700)

Claude Code agents kept running `go test`, `go build`, and `golangci-lint`
directly instead of using the Taskfile, which has the correct flags,
exclusions, and environment setup. The commands section listed `task`
commands but never prohibited direct usage, so the instruction lost
salience during long conversations.

Add an IMPORTANT callout after the commands block and a new "Things That
Will Bite You" section to make the requirement explicit and durable.

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: JAORMX

CLAUDE.md

@@ -23,6 +23,8 @@ task build-image      # Build container image
 task build-all-images # Build all container images
 ```
 
+**IMPORTANT**: Always use `task` commands. Never run `go test`, `go build`, or `golangci-lint` directly -- the Taskfile has correct flags, exclusions, and environment setup that direct commands miss.
+
 **Testing**: Ginkgo/Gomega for BDD-style tests. Unit tests for `pkg/` business logic; E2E tests for CLI commands.
 
 ## Available Subagents
@@ -84,6 +86,11 @@ Detailed rules are in `.claude/rules/` (loaded automatically when matching files
 
 When making changes that affect architecture, update relevant docs in `docs/arch/`. See `docs/arch/README.md` for structure.
 
+## Things That Will Bite You
+
+- Running `go test ./...` or `golangci-lint run` directly skips Taskfile configuration (exclusions, flags, formatting). Always use `task test`, `task lint-fix`, etc.
+- After modifying API handlers or CLI commands, run `task docs` to regenerate CLI documentation.
+
 ## Evolving Conventions
 
 When a developer states a preference, convention, or correction during conversation (e.g., "we should use X instead of Y", "don't do Z", "always prefer A over B"), you MUST: