chore: add SwiftLint 0.65.0 with pinned CI version

[grdsdev]

Summary

• Adds SwiftLint 0.65.0 as a code-smell and correctness linter alongside the existing swift-format
• No changes to Package.swift — downstream consumers are unaffected
• Only the 25 rules that currently produce violations are disabled; the remaining ~75 default rules are enforced immediately
• Each disabled rule is a follow-up PR opportunity: remove it from disabled_rules once the violations are fixed

What changed

File	Purpose
.swiftlint.yml	Config scoped to Sources/Tests. Lists only the 25 rules with existing violations in disabled_rules; everything else runs and passes.
.github/workflows/ci.yml	New SwiftLint job pinned to 0.65.0 via portable_swiftlint.zip from GitHub releases, cached by version+OS, version-verified before running. Added to the ci-success required-jobs gate.
AGENTS.md	Documents the linting workflow.

Design notes

swift-format stays the layout authority. Rules that overlap with swift-format (e.g. trailing_comma, opening_brace, line_length) are disabled to avoid conflicts between the two tools.

Pinned version for reproducibility. CI downloads the exact 0.65.0 binary from GitHub releases and caches it — no brew resolution, no version drift. To upgrade: bump SWIFTLINT_VERSION in the workflow and commit.

Incremental adoption. Rather than a baseline file (which stores absolute paths and breaks across machines), violations are tracked by disabling only the rules that fire. Enable rules one-by-one in follow-up PRs by removing entries from disabled_rules.

Currently disabled rules and their violation counts:

Rule	Count
line_length	339
trailing_comma	139
identifier_name	128
non_optional_string_data_conversion	56
opening_brace	40
type_body_length	35
file_length	32
function_body_length	29
force_try	26
comment_spacing	19
redundant_discardable_let	9
force_cast	9
type_name	6
multiple_closures_with_trailing_closure	6
optional_data_string_conversion	5
implicit_optional_initialization	5
for_where	4
nesting	3
cyclomatic_complexity	3
orphaned_doc_comment	2
closure_parameter_position	2
todo	1
function_parameter_count	1
function_name_whitespace	1
class_delegate_protocol	1

Testing

• swiftlint lint --strict → 0 violations, 0 serious in 211 files
• SwiftLint CI job passes with pinned 0.65.0 binary

[coveralls]

Coverage Report for CI Build 28930530953

Warning

Build has drifted: This PR's base is out of sync with its target branch, so coverage data may include unrelated changes.
Quick fix: rebase this PR. Learn more →

Coverage increased (+0.4%) to 83.384%

Details

• Coverage increased (+0.4%) from the base build.
• Patch coverage: 3 of 3 lines across 2 files are fully covered (100%).
• 247 coverage regressions across 9 files.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

247 previously-covered lines in 9 files lost coverage.

File	Lines Losing Coverage	Coverage
Sources/RealtimeV2/RealtimeChannelV2.swift	129	67.38%
Sources/RealtimeV2/RealtimeClientV2.swift	44	86.76%
Sources/Auth/AuthClient.swift	32	87.22%
Sources/Auth/Types.swift	20	80.43%
Sources/Storage/StorageFileApi.swift	8	97.81%
Sources/Supabase/SupabaseClient.swift	7	67.18%
Sources/Auth/Internal/Keychain.swift	5	37.23%
Sources/Auth/Internal/JWTAlgorithm.swift	1	50.0%
Sources/Auth/Storage/KeychainLocalStorage.swift	1	41.67%

---

Coverage Stats

Relevant Lines:	9449
Covered Lines:	7879
Line Coverage:	83.38%
Coverage Strength:	37.58 hits per line

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💛 - Coveralls

[spydon]

I guess this should also be pinned somehow (if we want the same security as for the actions)? Because github releases can change...