docs: add irmars repo page, sidebar entry, and overview row

[dobby-coder]

The encryption4all/irmars repo was created on 2026-05-18 and is now a published crates.io dependency consumed by pg-core, pg-cli, and pg-pkg (encryption4all/postguard#192). It is missing from postguard-docs.

Source PRs:

• Add release-plz automated release pipeline irmars#1 — Add release-plz automated release pipeline (initial setup)
• Bump dependencies to current major versions irmars#2 — Bump dependencies to current major versions
• chore: release v0.2.2 irmars#3 — release v0.2.2 (first published crates.io release)
• ci: enforce Conventional Commits and modernize all workflows irmars#4 — ci: enforce Conventional Commits and modernize all workflows
• ci: bump irmago to v0.19.2 and point scheme download at schemes.yivi.app irmars#5 — ci: bump irmago to v0.19.2 and point scheme download at schemes.yivi.app
• chore: consume irmars from crates.io and bump reqwest to 0.12 postguard#192 — chore: consume irmars from crates.io and bump reqwest to 0.12

Repo description: "Rust library for interfacing with irma servers." Forked from tweedegolf/irmars (dormant since 2021); the encryption4all fork is now published as the irmars crate on crates.io. Existing use irma::... call sites are unchanged via the Cargo package = "irmars" rename.

What needs to change

1. Create docs/repos/irmars.md following the structure of existing repo pages (e.g. docs/repos/ibs.md, docs/repos/pg-curve.md). Cover:
   • One-line summary and link to https://github.com/encryption4all/irmars
   • Why the fork exists (upstream dormant; needed reqwest 0.12 + thiserror 2.0 to clear unmaintained transitives)
   • That it is published on crates.io as irmars
   • How it is consumed in postguard via the package = "irmars" Cargo rename so use irma::... keeps working
2. Add irmars to the Cryptographic Libraries section of the sidebar in docs/.vitepress/config.mts (next to pg-curve, ibe, ibs).
3. Add an irmars row to the repos table in docs/repos/overview.md and the architecture diagram if appropriate.

Verification

• npx vitepress build docs must succeed.
• docs/.vitepress/dist/repos/irmars.html must exist.

This agent will pick this up on the next worker spawn.

/dobby

[dobby-coder]

Dobby has heard the call! Dobby will eagerly add the missing irmars page, sidebar entry, and overview row to the docs. Dobby is on his way!

[dobby-coder]

Plan

1. Create docs/repos/irmars.md modeled on pg-curve.md (also a fork-with-purpose): summary, link, fork rationale (upstream dormant since 2021; needed reqwest 0.12 + thiserror 2.0 to clear unmaintained transitives), crates.io publication, and how postguard consumes it via package = "irmars" so use irma::... keeps working.
2. Add irmars to the Cryptographic Libraries sidebar group in docs/.vitepress/config.mts.
3. Add an irmars row to the Cryptographic Libraries table in docs/repos/overview.md and extend the dependency graph to show irmars feeding pg-core / pg-pkg / pg-cli.
4. Run npx vitepress build docs and confirm docs/.vitepress/dist/repos/irmars.html exists.
5. Open a draft PR, assign rubenhensen, flip to ready when CI is green.