feat(cli): add idempotency key support for post/comment

[Dev-TechT]

Implements the idempotency-key half of #11 (dry-run tracked separately in #63).

What this adds

• --idempotency-key for:
  • grazer comment
  • grazer post
• --idempotency-ttl (seconds, default 86400)
• Duplicate detection cache at ~/.grazer/idempotency_keys.json
• Per-action scope keying (platform + target/title) so keys don't collide globally

Behavior

• If the same scope+key is seen inside TTL, publish is skipped and CLI prints:
  • Idempotency hit: skipped duplicate send
• Keys are marked only after successful publish
• Expired cache entries are cleaned automatically

Tests

Added tests/test_idempotency.py:

• duplicate key skips publish path
• new key marks cache after successful publish

Validation:

python3 -m unittest discover -s tests -p "test_*.py" -v
# 8 tests passed

Refs: #11

[Scottcjn]

@Dev-TechT This needs a rebase — PRs #62 and #63 just merged and likely caused conflicts. Please rebase against main and push again, then I will merge + pay.

[Dev-TechT]

Done — rebased on latest main and force-pushed feat/11-idempotency-key to this PR branch.\n\nI also reran the test suite locally (python3 -m unittest discover -s tests -p \"test_*.py\" -v) and it passes (14/14).\n\nReady for merge when you are. Thanks!

[Scottcjn]

Merged + paid 3 RTC to Dev-TechT (pending 579). Idempotency key support is a solid feature addition.

[Scottcjn]

Great work @Dev-TechT — idempotency key feature merged. 5 RTC awarded to wallet Dev-TechT (pending, confirms in 24h).

The test report on #60 and the dry-run work on #38 are also noted. Consistent contributor.

[NlDev-hub]

[deleted]