What does this PR do?

Fixes the remaining shared CI failures after #25957.

There are two small test-isolation fixes here:

1. Discord e2e mock surface: history backfill now catches discord.Forbidden and uses discord.MessageType / discord.Object, but the e2e mock still exposed those as generic MagicMock attributes. That made the expected fallback path crash with TypeError: catching classes that do not inherit from BaseException is not allowed.
2. Nous provider parity helper: a few provider-parity tests instantiate the Nous Portal path without passing a model. After the minimum-context guard, that empty model resolves to a 15K fallback context and fails before the tests reach the provider-format assertions. The helper now uses gpt-5 for Nous parity tests, matching what those tests assert against later anyway.

Related Issue

Follow-up to #25957 and latest main Tests run 25895188143. Does not close a separate issue.

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 🔒 Security fix
• 📝 Documentation update
• ✅ Tests (adding or improving test coverage)
• ♻️ Refactor (no behavior change)
• 🎯 New skill (bundled or hub)

Changes Made

• tests/e2e/conftest.py
  • Adds discord.Forbidden as an exception class in the e2e Discord mock.
  • Adds deterministic discord.MessageType.default / reply values for history-context filtering.
  • Adds a minimal discord.Object(id=...) mock for cached-history after= support.
• tests/run_agent/test_provider_parity.py
  • Makes the shared test helper pass gpt-5 for Nous provider tests when a model is not provided explicitly.

How to Test

1. Reproduce the failed latest-main e2e nodes from run 25895188143.
2. Run the failed provider-parity nodes from PR CI.
3. Run the focused Discord e2e file.
4. Run the full e2e suite plus provider-parity file.

Validation run locally with scripts/run_tests.sh:

./scripts/run_tests.sh -n 0 tests/e2e/test_discord_adapter.py -q --tb=short
# 6 passed

./scripts/run_tests.sh -n 0 \
  tests/run_agent/test_provider_parity.py::TestDeveloperRoleSwap::test_developer_role_via_nous_portal \
  tests/run_agent/test_provider_parity.py::TestBuildApiKwargsNousPortal::test_includes_nous_product_tags \
  tests/run_agent/test_provider_parity.py::TestBuildApiKwargsNousPortal::test_uses_chat_completions_format \
  tests/e2e/test_discord_adapter.py \
  -q --tb=short
# 9 passed

./scripts/run_tests.sh -n 0 tests/run_agent/test_provider_parity.py tests/e2e -q --tb=short
# 149 passed, 7 skipped

git diff --check origin/main...HEAD
/home/w0lf/hermes-agent/venv/bin/python -m compileall -q tests/e2e/conftest.py tests/run_agent/test_provider_parity.py
/home/w0lf/hermes-agent/venv/bin/python -m ruff check tests/e2e/conftest.py tests/run_agent/test_provider_parity.py
# All checks passed

Validation Status

• Reproduced current-main e2e failure: 4 failed, 2 passed in tests/e2e/test_discord_adapter.py.
• Focused Discord e2e after fix: 6 passed in 2.65s.
• Newly failed provider-parity nodes plus Discord e2e after fix: 9 passed in 5.03s.
• Full e2e suite plus provider parity after fix: 149 passed, 7 skipped in 74.56s.
• git diff --check origin/main...HEAD passed.
• python -m compileall -q tests/e2e/conftest.py tests/run_agent/test_provider_parity.py passed.
• python -m ruff check tests/e2e/conftest.py tests/run_agent/test_provider_parity.py passed.
• Full pytest tests/ -q is not claimed here. This is intentionally a narrow CI unblocker.

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes (required for bug fixes, strongly encouraged for features)
• I've tested on my platform: Arch Linux, Python 3.11 venv via scripts/run_tests.sh

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — N/A, test fixture/helper only
• I've updated cli-config.yaml.example if I added/changed config keys — N/A
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — test-only changes, no runtime platform impact
• I've updated tool descriptions/schemas if I changed tool behavior — N/A

For New Skills

N/A

Screenshots / Logs

FAILED tests/e2e/test_discord_adapter.py::TestMentionStrippedCommandDispatch::test_mention_then_command - TypeError: catching classes that do not inherit from BaseException is not allowed
FAILED tests/e2e/test_discord_adapter.py::TestMentionStrippedCommandDispatch::test_nickname_mention_then_command - TypeError: catching classes that do not inherit from BaseException is not allowed
FAILED tests/e2e/test_discord_adapter.py::TestAutoThreadingPreservesCommand::test_command_detected_after_auto_thread - TypeError: catching classes that do not inherit from BaseException is not allowed
FAILED tests/e2e/test_discord_adapter.py::TestMentionStrippedCommandDispatch::test_text_before_command_not_detected - TypeError: catching classes that do not inherit from BaseException is not allowed

FAILED tests/run_agent/test_provider_parity.py::TestDeveloperRoleSwap::test_developer_role_via_nous_portal - ValueError: Model  has a context window of 15,000 tokens
FAILED tests/run_agent/test_provider_parity.py::TestBuildApiKwargsNousPortal::test_includes_nous_product_tags - ValueError: Model  has a context window of 15,000 tokens
FAILED tests/run_agent/test_provider_parity.py::TestBuildApiKwargsNousPortal::test_uses_chat_completions_format - ValueError: Model  has a context window of 15,000 tokens

149 passed, 7 skipped in 74.56s
All checks passed!