docs: refresh README hero with premium tagline and regulated-domains callout (#763)

Updates the tagline, adds Ontology Management/SKOS to the feature pills, swaps
the yellow-highlight subhead for a cleaner italic style, and surfaces a
regulated-domains teaser linking to the existing "Built for High-Stakes
Domains" section.

README.md

@@ -2,16 +2,20 @@
 
 <img src="Semantica Logo.png" alt="Semantica" width="420"/>
 
-### Context and Accountability Infrastructure for AI Agents
+### Graph-Native Infrastructure for Context and Accountable AI Systems
 
-#### <mark>**The Open Source Palantir for AI Agents**</mark>
+#### *The Open Source Palantir for AI Agents*
 
 > Ingest your enterprise data, extract what matters, build a Context Graph and knowledge graph (KG), and run graph analytics and causal reasoning over all of it, with full decision provenance baked in. Explainable, traceable, and trustworthy by design.
 
-**Decision Intelligence &nbsp;·&nbsp; Context Management &nbsp;·&nbsp; Deterministic Reasoning &nbsp;·&nbsp; Traceability**
+**Decision Intelligence &nbsp;·&nbsp; Context Management &nbsp;·&nbsp; Deterministic Reasoning &nbsp;·&nbsp; Ontology Management &nbsp;·&nbsp; SKOS Vocabularies &nbsp;·&nbsp; Traceability**
 
 **Open Source &nbsp;·&nbsp; Auditable &nbsp;·&nbsp; Governed &nbsp;·&nbsp; Self-Hostable &nbsp;·&nbsp; Zero Vendor Lock-In**
 
+#### Built for High-Stakes, Regulated Domains
+
+*Finance &nbsp;·&nbsp; Healthcare &nbsp;·&nbsp; Legal &nbsp;·&nbsp; Government &nbsp;·&nbsp; Defense &nbsp;&nbsp;([details ↓](#built-for-high-stakes-domains))*
+
 [![GitHub Stars](https://img.shields.io/github/stars/semantica-agi/semantica?style=flat-square&color=FFD700&logo=github&logoColor=white&label=Stars)](https://github.com/semantica-agi/semantica) [![GitHub Forks](https://img.shields.io/github/forks/semantica-agi/semantica?style=flat-square&color=6E40C9&logo=github&logoColor=white&label=Forks)](https://github.com/semantica-agi/semantica/network/members) [![Contributors](https://img.shields.io/github/contributors/semantica-agi/semantica?style=flat-square&color=2EA043&logo=github&logoColor=white)](https://github.com/semantica-agi/semantica/graphs/contributors) [![PyPI](https://img.shields.io/pypi/v/semantica.svg?style=flat-square&color=0066CC&logo=pypi&logoColor=white)](https://pypi.org/project/semantica/) [![Total Downloads](https://static.pepy.tech/badge/semantica?style=flat-square)](https://pepy.tech/project/semantica) [![Python 3.8+](https://img.shields.io/badge/python-3.8+-3776AB?style=flat-square&logo=python&logoColor=white)](https://www.python.org/) [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg?style=flat-square)](https://opensource.org/licenses/MIT) [![CI](https://img.shields.io/github/actions/workflow/status/semantica-agi/semantica/ci.yml?style=flat-square&label=CI)](https://github.com/semantica-agi/semantica/actions) [![Ask DeepWiki](https://deepwiki.com/badge.svg)](https://deepwiki.com/semantica-agi/semantica)
 
 [![Website](https://img.shields.io/badge/Website-getsemantica.ai-000000?style=flat-square&logo=googlechrome&logoColor=white)](https://getsemantica.ai/) [![Docs](https://img.shields.io/badge/Docs-docs.getsemantica.ai-0099FF?style=flat-square&logo=readthedocs&logoColor=white)](https://docs.getsemantica.ai/) [![Discord](https://img.shields.io/badge/Discord-Join%20Community-5865F2?style=flat-square&logo=discord&logoColor=white)](https://discord.gg/sV34vps5hH) [![Twitter/X](https://img.shields.io/badge/Follow-%40BuildSemantica-000000?style=flat-square&logo=x&logoColor=white)](https://x.com/BuildSemantica) [![YouTube](https://img.shields.io/badge/YouTube-Watch%20Demos-FF0000?style=flat-square&logo=youtube&logoColor=white)](https://www.youtube.com/watch?v=QfnNZg4-dZA) [![Changelog](https://img.shields.io/badge/Changelog-View-6E40C9?style=flat-square&logo=keepachangelog&logoColor=white)](CHANGELOG.md)