Prepare ACE Core 0.8.3 compatibility release

[eamirian]

What

• version ACE Core and its shipped identities as 0.8.3
• publish the exact-installed-Pack conformance seam and semantic source-time behavior already merged in Resolve exact installed Domain Pack artifacts #166 and Preserve semantic time in source mapping #170
• export the durable Intelligence build-host composer through the public Application package
• record bounded candidate evidence without changing historical 0.8.2 evidence
• keep schema v177, exactly eleven MCP tools, and the reference adapter 0.4.0 boundary unchanged

Why

The Market Intelligence consumer needs a released Core artifact that contains both ace.intelligence.conformance and the corrected publication/observation/ingestion time semantics. Core 0.8.2 predates both changes, so Market cannot honestly declare or lock a compatible dependency until this patch is public.

Root cause

Core main advanced after 0.8.2, while Market remained correctly pinned to the latest public 0.8 release. An isolated release-boundary test also exposed that ace.application.intelligence_build_host was not loaded by the package's public surface, making that conformance check depend on prior test imports.

User and developer impact

External Intelligence products can verify the exact installed Pack through public APIs and preserve truthful bitemporal provenance. Market can pin ace-core>=0.8.3,<0.9, regenerate only its current candidate artifacts, and leave every historical release packet unchanged.

Verification

• focused release, evidence, exact-Pack, boundary, source-mapping, and build-backend suite: 79 passed
• full non-e2e suite: 8,049 passed, 48 skipped, 251 deselected
• Ruff format and lint: passed
• lock and diff checks: passed
• wheel and sdist: built successfully; Twine 7.0.0 strict checks passed
• fresh external Python 3.12 environment: installed ace-core==0.8.3, imported ace.intelligence.conformance, loaded the public build-host export, and exposed exactly eleven MCP tools

Boundaries

This patch does not add a universal connector catalog, change schema head, widen authority, advance roadmap maturity, or claim completion of the 0.9 or 1.0 product gates.