feat(catalog): add IntroDB.app marker provider

[blurbery]

Why

I wanted Silo to have a second independent source for intro and credit markers instead of relying on TheIntroDB alone. This adds my new IntroDB.app provider to the catalog as a separate plugin, so server owners can enable either provider or run both together.

IntroDB.app exposes intro, recap, and outro timestamps through one public read endpoint. The plugin maps outro to Silo credits and does not need an account or API key.

Benefits

• Gives Silo another source when one database has incomplete coverage or is temporarily unavailable.
• Lets Silo merge the best intro and credit result per episode instead of treating one provider as all-or-nothing.
• Stores accepted markers on the Silo media row, so the next user reuses them without another provider request.
• Keeps the provider fetch-only, so it does not show submission controls or run contribution jobs.

Performance

Playback does not wait for this lookup. The server starts marker refresh in the background and queries enabled providers concurrently rather than serially.

The plugin makes one request for intro, recap, and outro, caps requests at three seconds, collapses identical concurrent lookups, rate limits traffic, caches complete results for 24 hours, caches incomplete/missing results for 15 minutes, and pauses after rate-limit or Cloudflare failures. This keeps provider trouble from piling work onto the server or slowing the players.

Related changes

• Safer fallback, caching, and Cloudflare handling for the existing TheIntroDB plugin: fix(markers): retry alternate IDs safely silo-plugin-markers-theintrodb#5
• New plugin source: https://github.com/blurbery/silo-plugin-markers-introdb-app
• Tested v0.1.0 release: https://github.com/blurbery/silo-plugin-markers-introdb-app/releases/tag/v0.1.0

Validation

• go test ./...
• Catalog generated with the repository updater from the published v0.1.0 release
• Linux amd64, Linux arm64, and Darwin arm64 release builds completed successfully
• Release checksums and platform manifests are published
• git diff --check

AI Disclosure

• Tool(s): OpenAI Codex
• Model(s): GPT-5
• Involvement: AI-assisted
• Review: I reviewed the provider API, caching and failure paths, Silo merge and persistence behavior, and Apple/Aether marker presentation together.

Upstream submissions

• Focused server implementation: fix(playback): refresh incomplete skip markers silo-server#792
• Focused Apple/Aether prompts, including Skip Credits: fix(player): show reliable skip prompts silo-apple#203

[coderabbitai]

Important

• 🔍 Trigger review

This repository does not receive automatic reviews because it has fewer than 10 stars.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 8f5429cd-1824-450f-b9f1-c558c0b714fc

---

_{Comment @coderabbitai help to get the list of available commands.}