fix(github): number unsafe findings and count the same unit on every surface

[aparajon]

Renders unsafe changes as a flat numbered list — one line per finding — on both the PR comment and the CLI, and makes every heading count the same unit the list shows.

• Numbered, flat findings. The heading advertises a count, so the list below is now an ordered list the reader can check it against, and a finding can be referenced by its number ("2 is the blocker"). A table with several joined findings gets one line per finding with the table name repeated, instead of a nested sub-list.
• One counting unit everywhere. The PR comment counted individual findings while the CLI counted changes, so the same apply could say "3 unsafe changes" in the terminal and "4" on the PR. Both surfaces now count findings, and the count always equals the number of lines rendered below it.

PR comment — before / after

Before:

⛔ Apply rejected: 3 unsafe changes detected

• orders:
  • Primary key column id has type int
  • Column created_at uses TIMESTAMP which overflows on 2038-01-19. Consider using DATETIME instead.
• users: Column rename detected in table users: email to email_address. …

After:

⛔ Apply rejected: 3 unsafe changes detected

1. orders: Primary key column id has type int
2. orders: Column created_at uses TIMESTAMP which overflows on 2038-01-19. Consider using DATETIME instead.
3. users: Column rename detected in table users: email to email_address. …

CLI — before / after (note the count now matches the list)

Before:

⛔ Apply blocked: 3 unsafe change(s) detected
  • users: DROP COLUMN email
  • orders: DROP TABLE
  • products:
      - MODIFY COLUMN price_cents: INT → SMALLINT (potential data loss)
      - DROP INDEX idx_category

After:

⛔ Apply blocked: 4 unsafe change(s) detected
  1. users: DROP COLUMN email
  2. orders: DROP TABLE
  3. products: MODIFY COLUMN price_cents: INT → SMALLINT (potential data loss)
  4. products: DROP INDEX idx_category

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This PR was written by an AI agent (Claude Code, model Claude Fable 5) on behalf of the author.