Add harness certification matrix

README.md

@@ -256,8 +256,14 @@ Framework discovery is read-only:
 
 ```bash
 tree-ring integrations scan --source-root .
+tree-ring integrations certify --source-root .
 ```
 
+- `integrations certify` writes non-mutating harness evidence under
+  `target/tree-ring-certification/harness/` and updates
+  `target/tree-ring-certification/evidence-index.json`. Pass, fail, and skip
+  states are evidence records, not broad compatibility claims.
+
 It looks for local markers for DOX, Revolve, Codex, Claude Code, Agent Zero/A0,
 Goose, OpenCode, Hermes, and Pi, then suggests next steps without editing those
 tools' configuration. JSON output records whether each marker came from the

crates/tree-ring-memory-cli/Cargo.toml

@@ -16,6 +16,7 @@ name = "tree-ring"
 path = "src/main.rs"
 
 [dependencies]
+chrono.workspace = true
 clap.workspace = true
 ratatui.workspace = true
 serde.workspace = true