docs(platforms): schema-driven platform facts knowledge base with CI conformance

.github/workflows/platform-schema-conformance.yml

@@ -0,0 +1,27 @@
+name: platform-schema conformance
+
+# Verify docs/platforms/schema/*.toml stays in sync with the code: structural
+# schema validation + that every `source` code-ref still exists in the tree.
+# Runs on any change to the schema files, the template, or the checker itself.
+on:
+  pull_request:
+    paths:
+      - "docs/platforms/schema/**"
+      - "docs/platforms/_template.toml"
+      - "crates/platform-schema/**"
+  push:
+    branches: [main]
+    paths:
+      - "docs/platforms/schema/**"
+      - "docs/platforms/_template.toml"
+      - "crates/platform-schema/**"
+
+jobs:
+  conformance:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      # Standalone crate (serde + toml only); excluded from the root workspace
+      # so it builds without the heavy adapter crates.
+      - run: cargo test --manifest-path crates/platform-schema/Cargo.toml

CONTRIBUTING.md

@@ -172,6 +172,18 @@ gh run view <run_id> --repo openabdev/openab --json conclusion -q .conclusion
 - Run `cargo clippy` and address warnings
 - Keep PRs focused — one feature or fix per PR
 
+## Platform Schema
+
+When modifying a platform adapter (`crates/openab-gateway/src/adapters/*.rs`), check whether the change affects the platform's documented capabilities or feature status. If it does, update the corresponding `docs/platforms/schema/<platform>.toml`.
+
+See [`docs/platforms/README.md`](docs/platforms/README.md) for:
+- The three-schema structure (capability, feature-support, quirks)
+- How to add a new feature to the closed set
+- How to add a new platform
+- Architecture: TOML (machine facts) vs `docs/<platform>.md` (human setup guide)
+
+CI runs conformance tests on schema changes — missing features, invalid enums, or broken code-ref `source` fields will fail the build.
+
 ## PR Lifecycle
 
 Every PR follows a label-driven lifecycle that keeps the review loop moving.

Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
 members = ["crates/openab-core", "crates/openab-gateway"]
-exclude = ["openab-agent"]
+exclude = ["openab-agent", "crates/platform-schema"]
 
 [package]
 name = "openab"

crates/platform-schema/.gitignore

@@ -0,0 +1 @@
+/target

crates/platform-schema/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "platform-schema"
+version = "0.1.0"
+edition = "2021"
+publish = false
+description = "Authoritative types + conformance tests for docs/platforms/schema/*.toml"
+
+# Standalone crate (excluded from the root workspace) so it builds independently
+# of the heavy adapter crates. The serde structs below ARE the schema; each
+# schema/<platform>.toml deserializes into `Platform`.
+#
+# Run:  cargo test        (from this directory)
+
+[dependencies]
+serde = { version = "1", features = ["derive"] }
+toml = "0.8"