feat: 独立成仓库，自己拥有契约文件

agent 从 simadmin-relay 拆出来，作为公开仓库：安装命令要由节点执行，而节点没有凭据，所以
二进制必须放在匿名可读的地方，而 relay 源码与 IPA 继续私有。

拆出来之后有一处必须改，不是搬文件：`contracts/agent-policy.json` 原先由 relay 仓库拥有、
agent 侧是 vendored 副本（Makefile 从 `../contracts/` 拷、policy_test.go 断言两份相等）。
现在反过来——**agent 拥有策略**，因为 agent 是执行它的那一方，让它去拷贝一份住在别处的文件
本来就是别扭的。relay 保留 vendored 副本（它的限额从同一组数字推导），而两侧的一致性不再
靠构建期比较（跨仓库的构建期比较谁也做不了），改由运行时保证：agent 在握手时上报策略摘要，
relay 拿自己那份比对，在 `/v1/status` 里逐节点给出 `policyMatches`。这比原来的测试更强，
因为它比的是**实际部署的那两份**，而不是两个 checkout 里的文件。

`contracts/test-vectors.json` 同理：Go 实现生成它（`make vectors`），relay 的 Node 参考实现
与 app 的 Swift 测试从 vendored 副本重算。实测重新生成的结果与 relay 那份逐字节相同。

systemd 单元的 `Documentation=` 指向本仓库。`VERSION` 提到 1.0.0。

20 个提交的历史完整保留（filter-branch 按子目录抽取）。

Makefile

@@ -1,21 +1,31 @@
-POLICY_SRC := ../contracts/agent-policy.json
+# This repository owns the authorisation surface: the agent is what enforces it, so it is not a copy of
+# a file that lives somewhere else. `contracts/agent-policy.json` is embedded in the binary and is the
+# source of truth; the relay vendors a copy and the two are compared at runtime, by the policy digest the
+# agent reports in its handshake.
+POLICY_SRC := contracts/agent-policy.json
 POLICY_DST := internal/policy/agent-policy.json
 # The systemd unit is embedded in the binary so that `msa-agent install` needs no route to anything but
-# the relay, and so the unit a node runs is the one its agent was built with. Vendored mechanically for
-# the same reason the policy is: an operator editing the copy under internal/ would be editing a file
-# the build overwrites, and TestVendoredUnitMatchesSystemd makes that loud.
+# the relay, and so the unit a node runs is the one its agent was built with. Vendored mechanically: an
+# operator editing the copy under internal/ would be editing a file the build overwrites, and
+# TestVendoredUnitMatchesSystemd makes that loud.
 UNIT_SRC   := systemd/msa-agent.service
 UNIT_DST   := internal/install/msa-agent.service
 # The version stamped into the binary, and the tag scripts/release.sh publishes under. It is the
 # agent's own version rather than the app's: the two are released together but a node can be running an
 # older agent than the phone, and the handshake's `agentBuild` field is what makes that visible.
-VERSION    ?= 0.3.0
+VERSION    ?= 1.0.0
 LDFLAGS    := -s -w -X main.version=$(VERSION)
 
-.PHONY: all vendor test vet build build-arm64 build-armv7 clean
+.PHONY: all vendor test vet fmt vectors build build-arm64 build-armv7 clean
 
 all: vet test build
 
+# Regenerates contracts/test-vectors.json. It is the Go implementation that generates them, and the
+# relay's Node reference implementation and the app's Swift tests recompute them from the result — three
+# implementations with no shared code, so agreement is evidence rather than a tautology.
+vectors:
+	@go run ./cmd/msa-vectors contracts/test-vectors.json
+
 # The policy is embedded, so the vendored copy is part of the binary. Keep the copy mechanical:
 # an operator editing internal/policy/agent-policy.json by hand would be editing a file the build
 # overwrites, and the drift test makes that mistake loud rather than quiet.