fix(audit): declare the partial flag on discord.role_changed - #216

Found while auditing the Details column for #215, fixed separately because it is
a different action and a different mechanism.

The bug

discord.role_changed has two writers, and both stamp a partial key on every
row:

• src/jobs/discord-roles.ts:143 — the deprovision path, writing
  { removed, cause, partial }
• src/jobs/discord-roles.ts:369 — the main sweep, writing
  { added, removed, tier, partial }

The PARTS entry declared added, removed, tier, and cause — not
partial. summarizeDetails counts undeclared keys toward the hidden-key
total, so every role-change row rendered a +1 more with nothing behind it.

Two costs. The +1 more was pure noise on rows where nothing was hidden, which
trains an admin to ignore the marker. And a row that was genuinely partial —
some roles failed to apply — announced that fact only as the same opaque count
it showed on every complete row, so the one case worth noticing was
indistinguishable from the noise.

The fix

One flag("partial", "partial") added to the declaration.

flag rather than scalar: it renders the word only when the value is truthy
while declaring the key either way, so complete rows say nothing instead of
carrying a partial false that would be noise on the overwhelming majority.
Placed last because it qualifies the whole change rather than naming a part of
it, and declared parts are never truncated (summarize.ts:405-407), so trailing
costs it no visibility.

Verification

Written test-first — the three new cases fail against the unfixed code:

AssertionError: expected '+alumni' to be '+alumni, partial'
AssertionError: expected '+alumni, +1 more' to be '+alumni'
AssertionError: expected '+alumni, +2 more' to be '+alumni, +1 more'

That last one is the bug stated precisely: partial inflating the hidden count
past the one key that was genuinely undeclared. All three pass after the change.

npm run typecheck, npm run lint, npm run format:check clean.
npm test → 92 files, 1490 tests passing. npm run build succeeds.

Scope

This fixes the one action. I did not systematically audit the other ~50
logAudit payload sites for the same declared-vs-written drift — that is a
broader sweep worth doing on its own, and the same class of bug would be
invisible in exactly the same way anywhere else it exists.

Touches summarize.ts alongside #215, but in a different region of PARTS
(the discord.* entries rather than the character-id ones). Either order
merges.

Summary by CodeRabbit

• Bug Fixes

  • Audit summaries now display the partial indicator only when applicable.
  • Prevented the partial field from being incorrectly counted as an undisclosed change when false.

• Tests

  • Added coverage for true, false, and undeclared audit fields.