Grow the BEC catalog with more languages (Ruby, PHP, Java, C#, Shell)

[DataDave-Dev]

Context

The catalog (becs/) currently covers Python, JS/TS, Go and Rust. becwright's value compounds with catalog breadth (the "network effect" in CLAUDE.md), and CONTRIBUTING.md documents "Adding a catalog BEC" using the generic forbid check — no code required.

Proposal

Add ready-to-import BECs for more ecosystems, each as becs/<id>.bec.yaml with intent + why_it_matters. Ideas:

• Ruby — no-binding-pry, no-puts-debugging
• PHP — no-var-dump, no-error-reporting-all
• Java — no-printstacktrace, no-system-out-println
• C# — no-console-writeline
• Shell — no-set-x-left-in

Acceptance criteria

• Each bundle parses (already covered by test_catalog_bundles_are_valid).
• Uses check: "becwright run forbid --pattern '...'".
• Listed in becs/README.md.
• One language per PR is welcome — easy to pick up.

See CONTRIBUTING.md → "Adding a catalog BEC" and the existing becs/no-debug-go.bec.yaml for the format.

[DataDave-Dev]

Split into one issue per language so each is an independent good first issue:

• Ruby — Catalog: Ruby BECs (no-binding-pry, no-puts-debugging) #65
• PHP — Catalog: PHP BECs (no-var-dump, no-error-reporting-all) #66
• Java — Catalog: Java BECs (no-printstacktrace, no-system-out-println) #67
• C# — Catalog: C# BECs (no-console-writeline) #68
• Shell — Catalog: Shell BECs (no-set-x-left-in) #69

Pick any of them — one language per PR, no code required (a catalog BEC is a single YAML using the generic forbid check).