fix(hermes): enforce trailing newline on patched hermes config

[vaibhavsrv]

Why this matters

In ods/scripts/patch-hermes-config.py, patch_config() conditioned adding a final newline on whether the unpatched original file already possessed one (trailing_newline = original.endswith("\n")). When migrating older template files or user-provided Hermes configs that omitted a terminating newline, the patch utility persisted the missing-newline state. This violated POSIX newline standards and caused YAML parsers and linting tools to flag \ No newline at end of file.

This change unconditionally appends a terminating newline (\n) to serialized YAML configs on write. All section preservation logic, model overrides, provider timeouts, and auxiliary configuration keys remain untouched.

Validation

• Baseline reproduction: Patching a Hermes configuration file lacking a trailing newline resulted in an output file also lacking a trailing newline.
• Post-fix verification: Running ods/tests/test_patch_hermes_config_trailing_newline.py validates that patching a config lacking a trailing newline outputs valid YAML ending with \n, applies specified model overrides, and remains idempotent on subsequent runs.
• Telemetry: Hermes test suite: test_patch_hermes_config_trailing_newline.py passes cleanly (exit code 0). Wired into Linux CI workflow under Hermes Slash Worker Prune Tests.

Overlap check

• fix(hermes): validate config path is a file in patch-hermes-config.py #5602: Addressed context length validation in patch-hermes-config.py.
• fix(classify-hardware): guard non-numeric and negative bounds in ram and vram parsing #6084 (PR 9): Addressed numeric argument parsing in classify-hardware.sh.
• Does not modify any default YAML templates, prompt signatures, or runtime Hermes service arguments.

Risk / AI disclosure

AI-assisted investigation, implementation, and test regressions. This standardizes POSIX trailing newline formatting for patched Hermes YAML files. Independent human review and platform/runtime qualification remain gates. No running configuration, deployment or upstream merge changed.

Follow-up integration evidence

Composed with #6076, #6077, #6078, #6079, #6080, #6081, #6082, #6083, and #6084 at HEAD without conflicts. Production and test diffs passed together; Hermes worker and configuration checks 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.