[vaibhavsrv]

Why this matters

In ods/scripts/mode-switch.sh, switch_mode() checked LLM_BACKEND and ODS_MODEL_SWITCHBOARD casing using Bash 4 case-modification parameter expansion: ${configured_backend,,} and ${switchboard_mode,,}. On systems running Bash 3.2 (notably default macOS shells using /bin/bash), running mode-switch.sh immediately fails with /bin/bash: ${configured_backend,,}: bad substitution, preventing operators from inspecting mode status or switching inference targets.

This patch adopts portable tr '[:upper:]' '[:lower:]' case normalization, ensuring mode transitions and external routing validations execute reliably across both modern Bash 4+ and macOS default Bash 3.2 environments.

Validation

• Repro baseline: Executed mode-switch.sh cloud under /bin/bash with uppercase/mixed-case environment settings; confirmed failure with /bin/bash: ${configured_backend,,}: bad substitution.
• Post-fix: Verified ods/tests/test_mode_switch_bash32.py passes with exit code 0 under /bin/bash; switches mode cleanly and correctly enforces external LLM routing guardrails.
• CLI mode switch suites: 1 passed. New-test syntax and diff checks pass; new regressions wired into Linux CI.

Overlap check

• Probe the live model on the real llama-server host port #5860 (0xacee): Addressed LLM port fallback in build-installation-context.py.
• Authenticate Windows Lemonade status probes #5862 (0xacee): Addressed LITELLM_LEMONADE_API_KEY resolution in ods-host-agent.py without overlap in mode-switch.sh.
• fix(pixel-gateway): strip trailing slashes on provider baseUrl when resolving completions target #5872 (vaibhavsrv): Addressed trailing slash stripping on provider baseUrl in runtime gateway.

Risk / AI disclosure

AI-assisted investigation, implementation and CLI regressions. This strengthens shell compatibility for mode switching across POSIX and Bash 3.2 platforms, not daemon runtime execution. Independent human review and platform/runtime qualification remain gates. No running configuration, deployment or upstream merge changed.

Follow-up integration evidence

Composed with #5871 at 81b881c without conflicts. Production and test diffs passed together; mode-switch contracts remain intact.
Backlog composition was local-only (production/test diffs, excluding workflow/Makefile wiring); it is not an upstream merge or independent human approval. Declared live-review gates remain open.

[Lightheartdevs]

Thanks for this contribution. public-beta was promoted into main on 2026-09-24 and no longer receives changes, so we're closing pull requests that target it. This isn't a judgment on the change itself. If it's still needed, please rebase onto main and open a focused PR. See #7253 for details and the contribution policy.