feat(P01): CLI skeleton with Cobra, subcommand stubs, pre-push hook

Implements Phase 1 of v0.1 Foundation:
- go.mod with Go 1.25
- cmd/orca/main.go entry point
- internal/cli/root.go with global --json flag
- internal/cli/version.go (orca version)
- internal/cli/init.go (orca init - creates ~/.orca/)
- internal/cli/status.go (orca status - shows daemon info)
- internal/cli/node.go (orca node {join,leave,list} - stubs)
- internal/cli/job.go (orca job {run,list,stop,logs} - stubs)
- Makefile (build, test, lint, fmt, release)
- LICENSE (MIT)
- README.md with quickstart
- .gitignore
- .githooks/pre-push + scripts/trigger_coreci.sh (CoreCI trigger)
- Smoke tests in internal/cli/root_test.go

Verified: go build, go test, go vet, gofmt all pass.

---ci---
project: orca
phase: 1
milestone: v0.1
status: execute
req_covered:
  - REQ-001
  - REQ-002
  - REQ-013
  - REQ-015
  - REQ-016
  - REQ-019
  - REQ-024
---/ci---

scripts/trigger_coreci.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+# trigger_coreci.sh - Trigger CoreCI pipeline for the pushed branch
+# Invoked by .githooks/pre-push
+# Gracefully degrades if CoreCI API is unreachable (Gitea webhook is secondary path).
+
+set -uo pipefail
+
+CORECI_URL="${CORECI_URL:-https://git.cloudinit.dev/coreci/coreci}"
+GITEA_TOKEN="${GITEA_TOKEN:-}"
+
+if [ -z "$GITEA_TOKEN" ]; then
+  echo "  (skip: GITEA_TOKEN not set)"
+  exit 0
+fi
+
+while read local_ref local_sha remote_ref remote_sha; do
+  branch="${remote_ref#refs/heads/}"
+  if [ -z "$branch" ] || [ "$branch" = "HEAD" ]; then
+    continue
+  fi
+  echo "→ Triggering CoreCI for branch: $branch (${local_sha:0:7})"
+  payload=$(printf '{"repo":"coreci/orca","branch":"%s","ref":"%s"}' "$branch" "$local_sha")
+  if command -v curl >/dev/null 2>&1; then
+    curl -fsS -X POST "${CORECI_URL}/api/pipeline/run" \
+      -H "Authorization: token ${GITEA_TOKEN}" \
+      -H "Content-Type: application/json" \
+      -d "$payload" >/dev/null 2>&1 \
+      && echo "  ✓ CoreCI triggered" \
+      || echo "  (CoreCI trigger failed; pipeline may run via webhook)"
+  fi
+done