Persist iterate goals between CLI runs

[SimoneMariaRomeo]

Problem

sh1pt iterate goals is documented as the place to declare optimization targets, but the command only prints a stub and forgets values between runs.

Proposed scope

Persist local iterate goals in the sh1pt config directory, keep the documented sh1pt iterate goals set conversion=8% cpi=2.00 form working, and support a machine-readable --json view for future iterate run work.

Acceptance

• sh1pt iterate goals set key=value saves goals locally.
• sh1pt iterate goals lists saved goals in stable order.
• sh1pt iterate goals --json returns saved goals for automation.
• malformed goal assignments fail clearly.

Related to #133.

[Robertg761]

Submitted a focused PR for this issue:

• Persist iterate goals #172 Persist iterate goals between CLI runs.

What changed:

• sh1pt iterate goals set key=value persists local goals in the sh1pt config directory.
• sh1pt iterate goals lists saved goals in stable key order.
• sh1pt iterate goals --json returns machine-readable goals.
• malformed assignments fail clearly with key=value guidance.

Validation run locally:

• pnpm exec vitest run packages/cli/src/commands/iterate-goals.test.ts
• XDG_CONFIG_HOME=$tmp pnpm exec tsx packages/cli/src/index.ts iterate goals set conversion=8% cpi=2.00
• XDG_CONFIG_HOME=$tmp pnpm exec tsx packages/cli/src/index.ts iterate goals --json
• XDG_CONFIG_HOME=$tmp pnpm exec tsx packages/cli/src/index.ts iterate goals badassignment
• pnpm --filter @profullstack/sh1pt typecheck
• git diff --check