Add a changelog and map releases onto roadmap phases

Versions track the phases in the plan: a phase is released once its exit
criterion is met, not when its code lands. That keeps "released" meaning
something — v0.1.0 ships sim-engine and the routing libraries, and says plainly
that the gateway does not serve traffic yet.

scripts/gitea/milestones.py creates the matching Gitea milestones. Idempotent
and never destructive, so it can be re-run after the roadmap shifts.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

scripts/gitea/milestones.py

@@ -0,0 +1,166 @@
+#!/usr/bin/env python3
+"""Create the roadmap milestones in Gitea.
+
+Milestones mirror the phases in llmgw-plan.md §11 and the versions in
+CHANGELOG.md, so an issue can be filed against the phase that owns it.
+
+Idempotent: a milestone whose title already exists is left untouched, including
+its state and due date. Nothing is ever deleted.
+
+Usage:
+    GITEA_TOKEN=<token> scripts/gitea/milestones.py [--repo ilker/llmgw] [--dry-run]
+
+The token needs write access to the repository. Create one under
+Settings → Applications → Access Tokens with the `write:issue` scope.
+"""
+
+import argparse
+import json
+import os
+import sys
+import urllib.error
+import urllib.request
+
+DEFAULT_INSTANCE = "https://gitea.mynodes.xyz"
+DEFAULT_REPO = "ilker/llmgw"
+
+# Due dates are derived from the durations in plan §11 laid end to end from
+# 2026-09-16. They are estimates, not commitments; adjust them in Gitea rather
+# than here once reality disagrees.
+MILESTONES = [
+    {
+        "title": "v0.1.0 — Phase 0: skeleton and sim-engine",
+        "description": (
+            "CLI skeleton plus the fake inference engine everything else is tested "
+            "against. Exit criterion: sim-engine models batching, KV blocks, prefix "
+            "caching and cancellation, and exposes the §7.6 metric contract."
+        ),
+        "due_on": "2026-09-16T23:59:59Z",
+        "closed": True,
+    },
+    {
+        "title": "v0.2.0 — Phase 1: static router",
+        "description": (
+            "OpenAI handlers, streaming proxy with cancellation propagation, a static "
+            "endpoint list, the filter/score/pick pipeline and metric scraping.\n\n"
+            "Exit criterion: 1000 concurrent streams behind 3 sim-engines; upstream "
+            "cancellation on client disconnect verified; router overhead p99 < 2 ms."
+        ),
+        "due_on": "2026-09-30T23:59:59Z",
+    },
+    {
+        "title": "v0.3.0 — Phase 1.5: admission control",
+        "description": (
+            "Saturation detector, priority bands, round-robin tenant fairness, queue "
+            "capacity and TTL.\n\n"
+            "Exit criterion: while 500 concurrent batch requests flow through the "
+            "bronze band, interactive TTFT p99 in the platinum band stays under 1.5x "
+            "its idle value. This test stays in CI permanently."
+        ),
+        "due_on": "2026-10-07T23:59:59Z",
+    },
+    {
+        "title": "v0.4.0 — Phase 2: agent",
+        "description": (
+            "GPU and IB discovery, the engine interface, the process supervisor and "
+            "the control plane stream.\n\n"
+            "Exit criterion: start and stop a model on a real node via ctl."
+        ),
+        "due_on": "2026-10-21T23:59:59Z",
+    },
+    {
+        "title": "v0.5.0 — Phase 3: control plane",
+        "description": (
+            "SQLite store, catalog, inventory, single-node placement, reconciler, and "
+            "a dynamic EndpointSource for the router.\n\n"
+            "Exit criterion: shutting down a node moves its replicas elsewhere while "
+            "the router keeps serving."
+        ),
+        "due_on": "2026-11-11T23:59:59Z",
+    },
+    {
+        "title": "v0.6.0 — Phase 4: multi-node and fabrics",
+        "description": (
+            "Fabric identity, multi-node placement under the fabric constraint, NCCL "
+            "environment generation, replica-level failure handling.\n\n"
+            "Exit criterion: a 2-node replica on each fabric; killing a node rebuilds "
+            "the replica on the same fabric and never spreads it across two."
+        ),
+        "due_on": "2026-11-25T23:59:59Z",
+    },
+    {
+        "title": "v1.0.0 — Phase 5: production features",
+        "description": (
+            "Tenancy and budgets, routing profiles from configuration, the approximate "
+            "prefix tree, fallback models and pool spillover, ctl bench, tracing, "
+            "systemd units and documentation."
+        ),
+        "due_on": "2026-12-16T23:59:59Z",
+    },
+    {
+        "title": "Phase 6 — v2 ideas",
+        "description": (
+            "No due date; a parking lot. Precise KV index, admission displacement, "
+            "autoscaling with preemption, control plane HA, prefill/decode "
+            "disaggregation, LoRA routing, external providers, admin UI."
+        ),
+    },
+]
+
+
+def request(method, url, token, payload=None):
+    data = json.dumps(payload).encode() if payload is not None else None
+    req = urllib.request.Request(url, data=data, method=method)
+    req.add_header("Authorization", f"token {token}")
+    req.add_header("Content-Type", "application/json")
+    try:
+        with urllib.request.urlopen(req, timeout=30) as resp:
+            body = resp.read()
+            return json.loads(body) if body else None
+    except urllib.error.HTTPError as e:
+        detail = e.read().decode(errors="replace")[:300]
+        raise SystemExit(f"{method} {url} failed: {e.code} {detail}") from e
+
+
+def main():
+    ap = argparse.ArgumentParser(description=__doc__)
+    ap.add_argument("--instance", default=os.environ.get("GITEA_INSTANCE", DEFAULT_INSTANCE))
+    ap.add_argument("--repo", default=os.environ.get("GITEA_REPO", DEFAULT_REPO))
+    ap.add_argument("--dry-run", action="store_true", help="show what would be created")
+    args = ap.parse_args()
+
+    token = os.environ.get("GITEA_TOKEN", "")
+    if not token and not args.dry_run:
+        sys.exit("GITEA_TOKEN is not set (use --dry-run to preview)")
+
+    base = f"{args.instance.rstrip('/')}/api/v1/repos/{args.repo}/milestones"
+
+    existing = {}
+    if not args.dry_run:
+        for m in request("GET", f"{base}?state=all&limit=100", token) or []:
+            existing[m["title"]] = m
+
+    for spec in MILESTONES:
+        title = spec["title"]
+        if title in existing:
+            print(f"skip    {title}  (already exists, id={existing[title]['id']})")
+            continue
+        if args.dry_run:
+            print(f"create  {title}")
+            continue
+
+        payload = {"title": title, "description": spec.get("description", "")}
+        if "due_on" in spec:
+            payload["due_on"] = spec["due_on"]
+
+        created = request("POST", base, token, payload)
+        print(f"create  {title}  (id={created['id']})")
+
+        # The create endpoint ignores `state`, so close it separately.
+        if spec.get("closed"):
+            request("PATCH", f"{base}/{created['id']}", token, {"state": "closed"})
+            print(f"close   {title}")
+
+
+if __name__ == "__main__":
+    main()