Bump to 0.0.48: ship pane features, prune dead banner scripts, track MCP dev tools, add CHANGELOG #75

Summary

npm has jspod@0.0.47 but HEAD carries two unpublished pane features (#72 enrichment rendering, #74 collection pane) — 207 insertions / 28 deletions in data-browser-panes.js and examples/panes/, all within the published files set. Time for 0.0.48, plus housekeeping found while auditing the tree:

Changes

1. Bump version to 0.0.48 in package.json
2. Remove dead one-off scripts (tracked, referenced nowhere, not in files):
   • count-ascii.js, count-banner.js, jspod-ascii.js, verify-spacing.js — throwaway helpers from past ASCII-banner spacing work
3. Track the MCP dev tools currently sitting untracked in the working tree:
   • mcp.js — minimal Streamable-HTTP MCP client for the local pod
   • refresh-mcp-token.sh — re-mints a 1h owner token and registers the pod's /mcp endpoint in Claude Code
4. Record the diff: add CHANGELOG.md with the 0.0.48 entry and the diffstat vs 0.0.47, so what each publish shipped is recorded going forward

npm publish of 0.0.48 happens after merge (manual step).