Add pburl and pblastreport companion tools to the RPM

node-lookup output is useful for pivoting to Puppetboard, but there was no
quick way to turn a list of hosts into Puppetboard node-page URLs or to see
when each host last ran Puppet. These two tools close that gap and ship in the
same RPM so they are available wherever node-lookup is.

- Add pburl: reads hostnames from args or piped node-lookup output and prints
  "<host> <puppetboard-node-page-url>".
- Add pblastreport: prints "<host>\t<last-report-time>\t<url>" using
  report_timestamp from the PuppetDB v4 nodes endpoint. Supports --relative/-r
  (relative age) and --timezone/-z <IANA> (default: local timezone).
- Add internal/puppet package shared by both tools: config load, PuppetDB
  nodes query, Puppetboard URL construction, and no-TTY-safe stdin host reading.
- Add puppetboard_url config key (env NODE_LOOKUP_PUPPETBOARD_URL) to the
  shared config so config init/show scaffold it for the whole tool family.
- Build all three binaries individually (each is its own main package) and
  generate per-binary bash/zsh/fish completions in the Makefile, build-rpm.sh,
  and nfpm spec; cross-compile and attach all three per os/arch in the release
  pipeline.
- Document the tools, config key, and env var in AGENTS.md.

.gitignore

@@ -1,2 +1,9 @@
-node-lookup
+# built binaries (repo root only — not the cmd/ source dirs)
+/node-lookup
+/pburl
+/pblastreport
+# cross-compiled release artifacts (e.g. node-lookup-linux-amd64)
+/node-lookup-*
+/pburl-*
+/pblastreport-*
 dist/