Add Cargo workspace, crate skeletons and the gate

Implemented-By: Laguna S 2.1 (OpenCode)

docs/dependencies.md

@@ -0,0 +1,6 @@
+# Dependencies
+
+Every external crate has a row here. `scripts/check-dep-docs.sh` enforces it.
+
+| Crate | Version | Used by | Why |
+|---|---|---|---|

docs/egress.md

@@ -0,0 +1,9 @@
+# Egress
+
+Every outbound network call the project makes, at run time or in development. Nothing else is
+allowed.
+
+| When | From | To | What |
+|---|---|---|---|
+| Development | `cargo` | crates.io | Downloading the crates listed in `docs/dependencies.md` |
+| Development | `make audit` | github.com/rustsec/advisory-db | The RustSec advisory database, fetched by `cargo deny check advisories` |

docs/implementer-log.md

@@ -5,5 +5,6 @@ reviewer adds findings under "Reviews" once per milestone.
 
 | Task | Date | Status | Gate runs | First gate | Deviations | Notes |
 |---|---|---|---|---|---|---|
+| M1/01-workspace-and-gate | 2026-09-17 | done | 1 | pass | none | Crate skeletons, Cargo files and the given Makefile/deny.toml/test-gate-scripts.sh were already present untracked from a prior attempt; I verified them against the plan and created only the missing gate scripts, dependencies.md, egress.md and this log row. |
 
 ## Reviews