Add UC Open 2026 presentation (#20)

15-minute talk for the UC Open 2026 summit in Berkeley. Condenses the
long-form OSA platform deck to eight slides aimed at a broader audience:
OSC as a model, friction bridging, seven-community live footprint,
architecture that avoids RAG failure modes, YAML onboarding, public
status dashboard, real EEGLAB usage, and a join invitation.

Includes hand-drawn architecture SVG, publication-quality scientific
icons, puppeteer-captured 1920x1080 screenshots of live osc.earth,
demo.osc.earth, and status.osc.earth pages, and a pygmentize-rendered
YAML excerpt. Wires new page into mkdocs nav and presentations index.

Closes: UC Open 2026 prep

Author: neuromechanist

docs/osa/presentations/index.md

@@ -2,6 +2,7 @@
 
 Talks and presentations about the Open Science Assistant.
 
-| Date | Title | Description |
-|------|-------|-------------|
-| 2026 | [OSA Platform Overview](osa-platform.md) | Architecture, community onboarding, knowledge pipeline, and roadmap |
+| Date | Venue | Title | Description |
+|------|-------|-------|-------------|
+| 2026-04 | UC Open 2026, Berkeley | [A community-owned AI model for research tools](uc-open-2026.md) | 15-minute summit talk: OSC model, why not plain RAG, YAML onboarding, public status, invitation to join |
+| 2026 | Internal | [OSA Platform Overview](osa-platform.md) | Long-form walkthrough: architecture, community onboarding, knowledge pipeline, and roadmap |

docs/osa/presentations/slides/uc-open-2026/assets/Tableau10-B-NsZVaP.js

@@ -0,0 +1 @@
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docs/osa/presentations/slides/uc-open-2026/assets/arc-29arUbpb.js

@@ -0,0 +1 @@
+function t(r){return typeof r=="object"&&"length"in r?r:Array.from(r)}export{t as a};

docs/osa/presentations/slides/uc-open-2026/assets/array-BKyUJesY.js

@@ -0,0 +1 @@
+import{aH as o,aI as n}from"./main-BvA2blq7.js";const t=(a,r)=>o.lang.round(n.parse(a)[r]);export{t as c};

docs/osa/presentations/slides/uc-open-2026/assets/blockDiagram-68f4deed-Bn8LQiq7.js

@@ -0,0 +1 @@
+import{c as r}from"./graph-Ba9gv9y1.js";var e=4;function a(o){return r(o,e)}export{a as c};