[codex] add vertical connector plugins

[ashwinm-oai]

Summary

Adds app-backed plugin bundles for the connector conversion batch, excluding Datadog, Zoom, and Ramp as requested.

Included new plugin bundles:

• Similarweb

• LSEG

• S&P

• Datasite

• FactSet

• ZoomInfo

• Docusign

• Mixpanel

• Aiera

• Close

• Apollo

• Meticulate

• ThoughtSpot

• Midpage

Not included:

• Intercom (no released app)
• Zoho (can't connect)

Also updates the existing Quartr plugin manifest with the extracted brand color and three default prompts.

Implementation

Each new plugin includes:

• .codex-plugin/plugin.json with display metadata, brand color, icon references, and three default prompts
• .app.json pointing to the connector/app ID
• local logo assets pulled from the submitted URLs and referenced by composerIcon / logo
• a marketplace entry in .agents/plugins/marketplace.json

Categories were audited against comparable existing plugins. Similarweb, Mixpanel, Meticulate, and ThoughtSpot are categorized as Productivity; financial, market transcript, and legal research tools remain Research.

Validation

• Parsed all touched plugin manifests and .app.json files as JSON
• Verified referenced logo assets exist and parse as PNG/SVG images
• Parsed generated SVG icons as XML
• Parsed .agents/plugins/marketplace.json as JSON
• Ran git diff --check