Bump MSRV to 1.92, add GCP deployment files (#40)

* Bump MSRV to 1.92 and add GCP deployment files

rig-core 0.30 uses let_chains (stabilized post-1.87), which breaks
builds on Rust 1.85. Bump rust-version in Cargo.toml and both
Dockerfiles to 1.92 (verified working).

Add cloud deployment scaffolding:
- Dockerfile: multi-stage build for the main agent container
- deploy/cloud-sql-proxy.service: systemd unit for Cloud SQL Auth Proxy
- deploy/ironclaw.service: systemd unit for the IronClaw container
- deploy/setup.sh: VM bootstrap script (Docker, proxy, services)
- deploy/env.example: reference environment configuration

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* Address review feedback: harden deploy scaffolding

- Add comment explaining GATEWAY_HOST=0.0.0.0 and when to use 127.0.0.1
- Document /opt/ironclaw ownership model (root-owned, Docker reads as root)
- Switch cloud-sql-proxy service from User=root to DynamicUser=yes

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: Resolve clippy lints (Rust 1.93) and fix CI test workflow

- Fix 97 collapsible_if warnings using let-chains syntax (auto-fixed)
- Fix ptr_arg: change &PathBuf to &Path in pairing store functions
- Fix suspicious_open_options: add .truncate(false) to OpenOptions
- Fix too_many_arguments: add clippy allow on execute_status
- Fix unnecessary_unwrap: use if-let in repository.rs hybrid_search
- Gate unused EchoTool with #[cfg(test)]
- Add PairingStore argument to ChannelStoreData::new() test call sites
- Add skip guard for bundled channel test when WASM artifacts unavailable
- Split CI test workflow to exclude PostgreSQL-dependent integration tests

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: Address review feedback from ilblackdragon

- Add root check to setup.sh (exits with error if not root)
- Add warning comment to env.example about placeholder passwords
- Dockerfile.worker already uses rust:1.92 (no change needed)
- PR #41 overlap noted; will rebase after #41 merges

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: resolve 47 collapsible_if clippy warnings

Collapse nested if statements across the codebase to satisfy
clippy::collapsible_if on Rust 1.93.

Co-Authored-By: Claude Opus 4.6 <[email protected]>

---------

Co-authored-by: Claude Opus 4.6 <[email protected]>

src/tools/builder/testing.rs

@@ -326,20 +326,20 @@ impl TestHarness {
                 }
 
                 // Verify expected output
-                if let Some(ref expected) = test.expected_output {
-                    if &actual != expected {
-                        return TestResult {
-                            name: test.name.clone(),
-                            passed: false,
-                            duration,
-                            error: Some(format!(
-                                "Output mismatch:\nExpected: {}\nActual: {}",
-                                serde_json::to_string_pretty(expected).unwrap_or_default(),
-                                serde_json::to_string_pretty(&actual).unwrap_or_default()
-                            )),
-                            actual_output: Some(actual),
-                        };
-                    }
+                if let Some(ref expected) = test.expected_output
+                    && &actual != expected
+                {
+                    return TestResult {
+                        name: test.name.clone(),
+                        passed: false,
+                        duration,
+                        error: Some(format!(
+                            "Output mismatch:\nExpected: {}\nActual: {}",
+                            serde_json::to_string_pretty(expected).unwrap_or_default(),
+                            serde_json::to_string_pretty(&actual).unwrap_or_default()
+                        )),
+                        actual_output: Some(actual),
+                    };
                 }
 
                 // Verify expected fields
@@ -357,19 +357,19 @@ impl TestHarness {
                             };
                         }
 
-                        if let Some(ref expected_value) = field.value {
-                            if field_value != Some(expected_value) {
-                                return TestResult {
-                                    name: test.name.clone(),
-                                    passed: false,
-                                    duration,
-                                    error: Some(format!(
-                                        "Field '{}' mismatch: expected {:?}, got {:?}",
-                                        field.path, expected_value, field_value
-                                    )),
-                                    actual_output: Some(actual),
-                                };
-                            }
+                        if let Some(ref expected_value) = field.value
+                            && field_value != Some(expected_value)
+                        {
+                            return TestResult {
+                                name: test.name.clone(),
+                                passed: false,
+                                duration,
+                                error: Some(format!(
+                                    "Field '{}' mismatch: expected {:?}, got {:?}",
+                                    field.path, expected_value, field_value
+                                )),
+                                actual_output: Some(actual),
+                            };
                         }
                     }
                 }