[AZ-640] Bootstrap Rust workspace, CI/Docker, observability scaffold

Lands the first task of the implementation epic AZ-626: a cargo workspace
with 14 crates (shared + autopilot binary + 12 component crates), a
multi-stage Dockerfile + dev/test compose stacks, a Woodpecker CI pipeline,
the on-airframe systemd unit with flight-gate wiring, three environment
TOML configs, and the canonical entity catalogue from data_model.md as
`shared::models`.

Per-AC verification (full detail in
_docs/03_implementation/batch_01_cycle1_report.md):

- AC-1 cargo check --workspace clean
- AC-2 cargo test --workspace passes; per-crate it_compiles() <0.01 s
- AC-6 cargo build/test --no-default-features clean; VlmClient default
       impl returns VlmAssessment::disabled()
- AC-9 tracing-subscriber emits JSON logs with ts/level/target/fields
- AC-10 runtime::ensure_state_directories creates mapobjects/, audit/,
        pending_pushes/ under storage.state_dir

Deferred to external infra (artifacts written, verification re-runs in CI
and in downstream tasks):
- AC-3 Woodpecker runner; CI yml in place
- AC-4 docker-compose mocks land with AZ-660/AZ-644/AZ-675
- AC-5 SITL conformance lands with AZ-641/AZ-648/AZ-652
- AC-7 aarch64 cross-compile via cargo-zigbuild stage
- AC-8 systemd unit (Linux + systemd host)

Layering invariants from module-layout.md hold: shared (L1) imports
nothing; Layer 2 actor crates import only shared; Layer 3 coordinators
(operator_bridge, mission_executor) import only their documented Layer 2
deps; Layer 4 (scan_controller) imports its documented Layer 2 + Layer 3
deps; the autopilot binary (L5) is the only consumer of every component.

cargo fmt --all --check + cargo clippy --all-targets -- -D warnings both
clean. Jira AZ-640 transitioned to In Progress at the start of this batch;
the matching In Testing transition follows this commit.

Co-authored-by: Cursor <cursoragent@cursor.com>

crates/scan_controller/src/lib.rs

@@ -0,0 +1,84 @@
+//! `scan_controller` — central typed state machine.
+//!
+//! States per architecture.md §5: `ZoomedOut | ZoomedIn { roi, hold_started_at }
+//! | TargetFollow { target_id, started_at }`. Full behaviour-tree spec lives in
+//! `system-flows.md §F4`.
+//!
+//! Real implementation lands in:
+//! - AZ-682 `scan_controller_state_machine`
+//! - AZ-683 `scan_controller_poi_queue_and_window`
+//! - AZ-684 `scan_controller_evidence_ladder`
+//! - AZ-685 `scan_controller_mapobjects_dispatch`
+//! - AZ-686 `scan_controller_gimbal_issuance`
+
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+use shared::error::{AutopilotError, Result};
+use shared::health::ComponentHealth;
+use shared::models::operator::OperatorCommand;
+
+const NAME: &str = "scan_controller";
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(tag = "state", rename_all = "snake_case")]
+pub enum ScanState {
+    ZoomedOut,
+    ZoomedIn { roi: Uuid, hold_started_at_ns: u64 },
+    TargetFollow { target_id: Uuid, started_at_ns: u64 },
+}
+
+pub struct ScanController;
+
+impl ScanController {
+    pub fn new() -> Self {
+        Self
+    }
+
+    pub fn handle(&self) -> ScanControllerHandle {
+        ScanControllerHandle
+    }
+}
+
+impl Default for ScanController {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct ScanControllerHandle;
+
+impl ScanControllerHandle {
+    pub async fn tick(&self) -> Result<()> {
+        Err(AutopilotError::NotImplemented(
+            "scan_controller::tick (AZ-682)",
+        ))
+    }
+
+    pub async fn submit_operator_cmd(&self, _command: OperatorCommand) -> Result<()> {
+        Err(AutopilotError::NotImplemented(
+            "scan_controller::submit_operator_cmd (AZ-682)",
+        ))
+    }
+
+    pub fn state(&self) -> ScanState {
+        ScanState::ZoomedOut
+    }
+
+    pub fn health(&self) -> ComponentHealth {
+        ComponentHealth::disabled(NAME)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_compiles() {
+        let h = ScanController::new().handle();
+        assert!(matches!(h.state(), ScanState::ZoomedOut));
+        assert_eq!(h.health().level, shared::health::HealthLevel::Disabled);
+    }
+}