chore: add .editorconfig for consistent formatting

[hasna-identity]

Objective

chore: add .editorconfig for consistent formatting

Add a standard root .editorconfig to open-banking (github.com/hasna/banking): root=true, UTF-8, LF line endings, insert a final newline, trim trailing whitespace, 2-space indent for JS/TS/JSON/YAML/MD (preserve trailing whitespace for *.md). Match the repo's prevailing existing style. Do NOT reformat existing files or change product code. Scope: the .editorconfig file only. Open a PR against the d

VERIFIED 2026-07-29 against this repository's HEAD via the GitHub contents API: there is NO .editorconfig in the repo, so this is still needed.
Add the root .editorconfig ONLY. Do NOT reformat any existing file and do NOT touch product code — the diff should be exactly one new file.
Before writing it, inspect the repo's prevailing style (indent width actually used in src/, whether files end with a trailing newline) so the file describes what the repo already does instead of imposing a new one.
Acceptance: bun install succeeds, bun run typecheck (if the repo has one) and bun test are still green, and git diff --stat against the base shows only .editorconfig. No network, no credentials needed.

Verification

• policy source: base 7caf8d0 (immutable commit — agent-proof)
• containment: env — allowlist env, non-login shell, run-scoped HOME (registry auth seeded for install)
• install: pass
• typecheck: pass
• lint: pass
• build: pass
• test: pass
• doctor (ci): ok — 11 checks passed (1 advisory)

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Run run_6954ffd281eb · backend codewith · task 300f5d17-c11d-4ab3-ac93-cba3606a72db
🏭 Generated by @hasnaxyz/factory

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[andrei-hasna]

[REVIEW] GO — #6 @ 6f2127b — lens: correctness+security+gates, reviewer Augustus (1 of 1)

What I ran, with exit codes:

• git log --oneline origin/main..HEAD exit 0: one commit, 6f2127b chore: add .editorconfig for consistent formatting.
• git diff origin/main...HEAD --stat exit 0: .editorconfig | 14 ++++++++++++++, one file changed.
• bun install exit 0.
• bun run typecheck exit 0. The repo defines typecheck as tsc --noEmit.
• bun test exit 0. Result: 131 pass, 0 fail across 11 files.

What I read:

• Full PR diff for .editorconfig via git diff --full-index origin/main...HEAD -- .editorconfig.
• Full changed file .editorconfig.
• Repo scripts and gate definitions in package.json.
• TypeScript project context in tsconfig.json and tsconfig.build.json.
• CI gate context in .github/workflows/ci.yml.
• Packaging/ignored-file context in .gitignore.
• README context for package behavior and safety posture.
• Repo file layout for src, tests, scripts, and .github.
• Existing whitespace/tab scan with rg -n "\\t|[ ]+$" --glob '!bun.lock' --glob '!dist/**' ., which returned no matches.

Blocking P0/P1 findings:

• None. The PR adds a root .editorconfig only; it does not change runtime code, build scripts, tests, packaging outputs, credential handling, provider behavior, state mutation, or CI gates. The configured rules are consistent with the repository's TypeScript/YAML/Markdown style, and the required gates are green.

Non-blocking follow-ups:

• None.