Merge pull request 'feat: sign in from any computer, no private network needed' (#3) from feat/public-link-endpoint into main

granthi-link is now public at https://granthi-link.shre.ai (cloudflared,
origin still tailnet-only), so the client defaults there instead of a tailnet
IP. Internal machines pass --server or GRANTHI_LINK_SERVER.

Two rollout traps recorded in the README: a third-level hostname
(link.granthi.shre.ai) fails TLS because Cloudflare Universal SSL covers
shre.ai and *.shre.ai only; and exposure REQUIRES trust_forwarded_for with
the tunnel as the sole trusted proxy, or every request looks like the tunnel
and one abuser spends everyone's rate budget.

178 tests.

README.md

@@ -29,8 +29,10 @@ git CLI only — same portability heritage as the estate's `gitea_sync.py` mesh.
 ## Quickstart (invited user)
 
 You need a shre-id account — an operator creates it; there is no open signup
-(see "Invite-only story"). You also need to be on the tailnet: the
-provisioning service is not publicly exposed yet.
+(see "Invite-only story"). You do **not** need to be on any private network:
+the provisioning service answers at `https://granthi-link.shre.ai`, which is
+the client's default server. Internal machines can still pass
+`--server http://100.111.127.127:3042` to reach it over the tailnet.
 
 ```sh
 git clone https://granthi.shre.ai/nirpa/granthi-sync.git
@@ -166,11 +168,18 @@ So:
 * **Our own machines** may join the tailnet — that is an operator action with
   an operator's judgement behind it.
 * **Customer devices never do.** Their transport is public HTTPS to
-  granthi-link and the forge through cloudflared. That is the same exposure
-  step already in the promotion window below, and it is what makes a genuinely
-  new computer able to onboard itself at all — today `link` only works from
-  inside the tailnet, which means "you can't set up a new computer without an
-  operator first" is the honest status.
+  granthi-link and the forge through cloudflared. **Done 2026-08-23:**
+  `https://granthi-link.shre.ai` fronts `:3042` on the `pulse-granthi-edge`
+  tunnel, so a new computer signs itself in with one command and never
+  touches the private network.
+
+  Two things that bit during that rollout, worth not rediscovering:
+  `link.granthi.shre.ai` fails TLS — Cloudflare's Universal SSL covers
+  `shre.ai` and `*.shre.ai`, **not** a third-level `*.granthi.shre.ai`, so
+  the hostname has to be second-level. And exposure REQUIRES
+  `trust_forwarded_for: true` with `trusted_proxies: ["100.107.37.98/32"]`
+  in the same change: behind the tunnel every request otherwise looks like
+  the tunnel itself, and one abuser would spend everybody's rate budget.
 
 ## Components
 
@@ -537,8 +546,10 @@ Shape this should take, so the next session does not re-litigate it:
 
 ## Promotion window (beta → prod)
 
-1. **Expose :3042** behind cloudflared (granthi.shre.ai vhost or
-   link.granthi.shre.ai) — today it is tailnet-only by design.
+1. ~~**Expose :3042** behind cloudflared~~ **DONE 2026-08-23** —
+   `https://granthi-link.shre.ai` (second-level, see above), origin stays
+   tailnet-only, `trust_forwarded_for` on with the tunnel as the only
+   trusted proxy.
 2. **Swap forge base URLs** in `/opt/granthi-link/config.json`:
    `gitea_base` → prod forge, `public_gitea_base` →
    `https://granthi.shre.ai`; the client default server URL moves to the

client/granthi_sync_client.py

@@ -87,7 +87,12 @@ ZITADEL_BASE = "https://id.shre.ai"
 DEVICE_CLIENT_ID = "386909715541590022"
 # ^ Zitadel native app "granthi-sync-device" (appId 386909715541524486) in
 #   project granthi-forge (386906525790109702); device-code + refresh grants.
-DEFAULT_SERVER = "http://100.111.127.127:3042"
+# Public by default: a genuinely new computer cannot be expected to join a
+# private network before it can sign in. The tailnet address still works and
+# is what internal machines should pass to --server.
+DEFAULT_SERVER = os.environ.get("GRANTHI_LINK_SERVER",
+                                "https://granthi-link.shre.ai")
+TAILNET_SERVER = "http://100.111.127.127:3042"
 DEVICE_SCOPE = "openid profile email"
 
 FORGE_PAGE_LIMIT = 50

tests/test_client.py

@@ -1102,5 +1102,23 @@ class TestPruneClockIsPersisted(GitScenarioBase):
         self.assertEqual(pruner.call_count, 0)  # no snapshot folders linked
 
 
+
+class TestDefaultServer(unittest.TestCase):
+    """A new computer must be able to sign in without joining a private
+    network first -- that is the whole point of exposing the endpoint."""
+
+    def test_default_server_is_public_https(self):
+        self.assertTrue(client.DEFAULT_SERVER.startswith("https://"),
+                        client.DEFAULT_SERVER)
+        self.assertNotIn("100.111.", client.DEFAULT_SERVER)
+
+    def test_env_override_wins_for_internal_machines(self):
+        import importlib
+        with mock.patch.dict(os.environ,
+                             {"GRANTHI_LINK_SERVER": "http://10.0.0.5:3042"}):
+            reloaded = importlib.reload(client)
+            self.assertEqual(reloaded.DEFAULT_SERVER, "http://10.0.0.5:3042")
+        importlib.reload(client)  # restore for the rest of the suite
+
 if __name__ == "__main__":
     unittest.main()