Initialize repository with harness code and assets

Initial import of all source code, config, and README assets: the
packages workspace (cli, core, server, web, docs, landing, skills),
build scripts, tooling config, and CI workflows.

Includes the data-layout revision made on this branch: the local data
root defaults to ~/.penguin/data (PENGUIN_HOME still overrides; the
installer keeps its binaries in ~/.penguin), and every Agent lives
under <project>/agents/<agent>/ — path helpers, the three
agent-enumeration scans, the system prompt, built-in Skills, tests
and docs all follow the new layout.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018ihk8iQuo3kv2aPjAYEPuR

packages/server/src/internal/dates.ts

@@ -0,0 +1,20 @@
+/**
+ * Local date helpers (same convention as core's Trace date directories: local timezone
+ * yyyy-mm-dd). Shared by the usage_records.date aggregation key and stats windows
+ * (today / last 7 days / last 30 days).
+ */
+
+/** Format a time as a local `yyyy-mm-dd` (4-digit year, zero-padded 2-digit month/day). */
+export function formatLocalDate(date: Date): string {
+  const year = date.getFullYear().toString().padStart(4, "0");
+  const month = (date.getMonth() + 1).toString().padStart(2, "0");
+  const day = date.getDate().toString().padStart(2, "0");
+  return `${year}-${month}-${day}`;
+}
+
+/** Subtract N days from a local date (used for the start of the last-7-days / last-30-days windows). */
+export function localDateMinusDays(date: Date, days: number): string {
+  const d = new Date(date);
+  d.setDate(d.getDate() - days);
+  return formatLocalDate(d);
+}