test(mock_assistant): HA testing suite — backbone, time toolkit, DataProvider, simulation engine

[zoe-codez]

Draft — part of a cross-repo HA testing-suite effort (hass + synapse + automation + home-automation).

What this adds (hass mock_assistant)

• Backbone (Pillar 1): entity.register(entity_id, initialState) post-boot registration API; re-anchored on the socket→MASTER_STATE single write path; unified EMIT_SLEEP settle primitive; MockServices loopback registry.
• Time toolkit (Pillar 2): fake-clock wrappers (set/advanceTo/advanceBy), solar anchoring, tick-based advance; UTC-literal TZ contract; upstream sliding-schedule case fixed.
• DataProvider interface (Pillar 3, pure): observedValues / worldAt / findMoment — no native deps.
• Simulation engine (Pillar 4): scripted scenario() timeline, seeded reproducible sim, matrix/cartesian, findMoment solver (throws on no match); chaos mode auto-registers entities.

Gates

• vitest: 331 pass / 5 skip (live-DB specs gated).

Heads-up for reviewers

This branch is stacked on three pre-existing local commits not yet on main (color_temp_kelvin dev-type fixes + a deps/eslint-10 upgrade, calver 26.6.13). They are not part of the testing-suite work — fold/rebase as you prefer before merge.

[codecov]

Codecov Report

❌ Patch coverage is 77.18750% with 73 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.35%. Comparing base (b391d25) to head (4e54622).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/mock_assistant/helpers/solar.mts	59.35%	63 Missing ⚠️
src/mock_assistant/services/services.service.mts	14.28%	6 Missing ⚠️
src/mock_assistant/services/entity.service.mts	83.33%	2 Missing ⚠️
src/mock_assistant/services/scenario.service.mts	99.04%	1 Missing ⚠️
src/mock_assistant/services/time.service.mts	97.50%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #253      +/-   ##
==========================================
- Coverage   81.79%   81.35%   -0.44%     
==========================================
  Files          47       50       +3     
  Lines        1774     2092     +318     
  Branches      197      243      +46     
==========================================
+ Hits         1451     1702     +251     
- Misses        322      389      +67     
  Partials        1        1              

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