fix(agent): preload jiter native parser

[teknium1]

Salvage of #33665 by @helix4u onto current main.

Summary

Preloads the OpenAI SDK's native jiter streaming parser during agent package import, so the first DeepSeek/OpenAI-compatible streaming request on Windows doesn't hit ModuleNotFoundError: No module named 'jiter.jiter'.

Root cause

OpenAI SDK lazy-imports openai.lib.streaming.chat._completions the first time a streaming response is consumed, from inside the SSE worker thread. That module does from jiter import from_json, which triggers jiter/__init__.py → from .jiter import * → load of the native .pyd. On some Windows installs this thread-load fails (likely an AV / file-lock / loader-state race), even though the same import jiter.jiter succeeds when run synchronously from the Hermes venv at a REPL.

Reproduced live by a Discord user (Lucien) on Windows + DeepSeek: direct import jiter.jiter printed jiter ok, but every streaming chat request failed with ModuleNotFoundError: No module named 'jiter.jiter'. Confirmed workaround:

.\venv\Scripts\python.exe -c "import jiter.jiter, runpy; runpy.run_module('hermes_cli.main', run_name='__main__')"

That preloads the native extension on the main thread before any Hermes code starts. The PR makes Hermes do the same automatically.

Changes

• agent/jiter_preload.py: best-effort importlib.import_module("jiter.jiter") + from jiter import from_json, runs at module import. Swallows exceptions so a truly missing/broken install still surfaces via the normal SDK error path.
• agent/__init__.py: imports jiter_preload so the side effect runs on first import agent.* (which happens very early in CLI/gateway startup via agent.portal_tags, agent.secret_sources, etc.).
• tests/agent/test_jiter_preload.py: happy path + ModuleNotFoundError fallback.

Validation

• scripts/run_tests.sh tests/agent/test_jiter_preload.py → 2/2 passed.
• Local python3 -c "import agent; from agent import jiter_preload; print(jiter_preload._JITER_PRELOADED)" → True, jiter.jiter in sys.modules.
• Author email already mapped in scripts/release.py.

Closes #33665. helix4u authorship preserved via rebase-merge.

Infographic

[github-actions]

🔎 Lint report: hermes/hermes-ce53310b vs origin/main

ruff

Total: 0 on HEAD, 0 on base (➖ 0)

🆕 New issues: none

✅ Fixed issues: none

Unchanged: 0 pre-existing issues carried over.

ty (type checker)

Total: 9522 on HEAD, 9521 on base (🆕 +1)

🆕 New issues (1):

Rule	Count
unresolved-import	1

First entries

agent/jiter_preload.py:29: [unresolved-import] unresolved-import: Cannot resolve imported module `jiter`

✅ Fixed issues: none

Unchanged: 5017 pre-existing issues carried over.

Diagnostics are surfaced as warnings — this check never fails the build.

[alt-glitch]

Salvage of #33665 by @helix4u onto current main. Both fix the same jiter preload issue on Windows — this PR preserves the original approach with maintainer authorship.