feat(miner-manage): local manage-phase CLI status command

[JSONbored]

Give a contributor a single CLI command to see the current state of every PR the miner is managing — portfolio + latest CI/gate status + outcome, read from the local SQLite state built in the foundation issues. Pure read/render, no actuation.

Deliverables

• packages/gittensory-miner/bin/gittensory-miner.js gains a status subcommand (mirroring the bin shebang/CLI-arg-parsing pattern from packages/gittensory-mcp/bin/gittensory-mcp.js)
• Renders a table: repo, PR#, branch, CI state, gate verdict, outcome, last-polled-at
• --json flag for machine-readable output
• Unit tests covering empty-portfolio, mixed-state portfolio, and the --json output shape

References

• packages/gittensory-mcp/bin/gittensory-mcp.js — CLI bin pattern (shebang, arg parsing) to mirror exactly
• packages/gittensory-miner/src/state/schema.ts (new, from schema-foundation issue) — the data source
• New: packages/gittensory-miner/bin/gittensory-miner.js (status subcommand)

[linear-code]

JSO-2422