fix: ignore SC2034 and SC2312 shellcheck rules in hadolint config

SC2034 (unused variable): The SNIPPET pattern in devcontainer-claude-bun
follows the official Anthropic Claude Code devcontainer (anthropics/claude-code).

SC2312 (pipe in command substitution): The grep|cut pattern in ralphex-fe
checksum verification handles empty results with an explicit check.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: gatezh

.hadolint.yaml

@@ -12,3 +12,11 @@ ignored:
   # pipefail SHELL not required — only one pipe exists (bun install)
   # and curl -f already fails on HTTP errors.
   - DL4006 # set SHELL option -o pipefail before RUN with pipe
+
+  # SNIPPET variable in devcontainer-claude-bun follows the official
+  # Anthropic Claude Code devcontainer pattern (anthropics/claude-code).
+  - SC2034 # variable appears unused
+
+  # Pipes inside command substitutions (e.g. grep | cut) are intentional;
+  # empty results are explicitly checked afterwards.
+  - SC2312 # pipe in command substitution masks return value