fix: gitvote passes a vote on an exact tie

[gbartolini]

Fix: gitvote passes a vote on an exact tie

Problem

gitvote decides a vote with in_favor_percentage >= pass_threshold
(src/results.rs),
where the denominator is the whole electorate rather than the votes cast:

in_favor_percentage = in_favor as f64 / allowed_voters.len() as f64 * 100.0;
...
passed: in_favor_percentage >= vote.cfg.pass_threshold,

The >= is the problem. At a flat 50, an even-sized electorate splitting
exactly down the middle clears the bar, so a 2-2 tie on a four-owner
repository, or a 3-3 split on a six-member committee, passed the motion.

Electorate	In favor	%	>= 50	Correct?
7	4	57.1	pass	yes
7	3	42.9	fail	yes
10	5	50.0	pass	no, that is a 5-5 tie
10	6	60.0	pass	yes

Odd-sized electorates were never affected: the percentage cannot land on
exactly 50, so >= 50 and > 50 agree.

A simple majority is strictly more than half. A percentage cannot express
"half plus one vote", so the bar has to sit just above 50 instead.

Fix

Value	Was	Why
50.01	50	The smallest possible majority of N voters is 50 + 100/N percent, which stays above 50.01 for any N up to 10000. Rejects an exact tie, accepts every real majority.
66.66	66	Two-thirds is 66.666…, so a flat 66 sat under its own bar (33 of 50 is 66.0 and would have passed). Deliberately not 66.67: for an electorate divisible by three the exact two-thirds computes to 66.6666…, which falls under 66.67 and would break a legitimate 2-of-3.

pass_threshold is an f64 in gitvote's config
(src/cfg_repo.rs)
with no integer constraint, so fractional values parse fine.

The thresholds GOVERNANCE.md describes in prose, "simple majority" and
"two-thirds", are unchanged. Only the encoding of them in the tooling was
wrong.

Scope

The threshold lives in two places, so both are changed in one pass:

1. cnpg-infra's scripts/render-gitvote-config.sh, which renders
   .gitvote.yml into every managed repository. Pushed direct to main as
   cloudnative-pg/cnpg-infra@8ed4bd9
   per that repo's documented bypass exception.
2. governance's hand-maintained .gitvote.yml (marked excluded: true in
   gitvote-policy.yaml, since the federated model gave it a profile per
   subproject committee plus a -removal variant of each).

35 repositories in total: 1 direct push, 34 pull requests.

Pull requests

Added to the existing dev/sync-generated-files PRs (17)

These repositories still had their generated-files sweep PR open, so the fix
went on as an extra commit rather than a separate PR.

• chore: sync generated files with cnpg-infra policy cloudnative-pg#11480
• chore: sync generated files with cnpg-infra policy charts#1014
• chore: sync generated files with cnpg-infra policy cnpg-headlamp-plugin#24
• chore: sync generated files with cnpg-infra policy cnpg-i#368
• chore: sync generated files with cnpg-infra policy cnpg-i-hello-world#275
• community-operators #1 (fork, link form: a cross-reference would resolve against the upstream network)
• chore: sync generated files with cnpg-infra policy docs#152
• chore: sync generated files with cnpg-infra policy grafana-dashboards#72
• kopia #11 (fork, link form: a cross-reference would resolve against the upstream network)
• chore: sync generated files with cnpg-infra policy machinery#320
• chore: sync generated files with cnpg-infra policy pgbouncer-containers#133
• chore: sync generated files with cnpg-infra policy plugin-barman-cloud#1101
• chore: sync generated files with cnpg-infra policy postgis-containers#140
• chore: sync generated files with cnpg-infra policy postgres-containers#508
• chore: sync generated files with cnpg-infra policy postgres-keycloak-oauth-validator#21
• chore: sync generated files with cnpg-infra policy postgres-trunk-containers#155
• chore: sync generated files with cnpg-infra policy webtest#15

New dev/gitvote-majority-threshold PRs (17)

These repositories had already merged their sweep PR, so the fix needed a
fresh branch. governance is here because its file is hand-maintained and
never had a sweep PR at all.

• fix: require a strict majority to pass a gitvote vote .github#14
• fix: require a strict majority to pass a gitvote vote .project#8
• fix: require a strict majority to pass a gitvote vote api#22
• fix: require a strict majority to pass a gitvote vote artifacts#23
• fix: require a strict majority to pass a gitvote vote artwork#8
• fix: require a strict majority to pass a gitvote vote barman-cloud#302
• fix: require a strict majority to pass a gitvote vote chaos-testing#9
• fix: require a strict majority to pass a gitvote vote ciclops#41
• fix: require a strict majority to pass a gitvote vote cloudnative-pg.github.io#464
• fix: require a strict majority to pass a gitvote vote cnpg-i-machinery#337
• fix: require a strict majority to pass a gitvote vote cnpg-playground#113
• fix: require a strict majority to pass a gitvote vote cnpg-template#5
• fix: require a strict majority to pass a gitvote vote daggerverse#184
• fix: require a strict majority to pass a gitvote vote github-test#3
• fix: require a strict majority to pass a gitvote vote #79
• chore: require a strict majority to pass a gitvote vote klio#279
• fix: require a strict majority to pass a gitvote vote postgres-extensions-containers#342

Direct push (1)

• cloudnative-pg/cnpg-infra@8ed4bd9 on main

Notes

• The governance PR touches only .gitvote.yml, not GOVERNANCE.md, so the
  amendment automation does not fire on it. Confirmed: no vote was opened.
• cnpg-infra is the source of truth. Since the renderer changed first, a
  later sync-ownership-files.sh run will not revert any of these.
• Verified across all 35 repositories: every profile parses as a float,
  50.01 or 66.66, and every branch matches its remote.