fix(connections): persist SSL settings and honor a URL's sslmode (#36)

Connecting to a managed provider (Neon in the report) failed with
"connection is insecure (try using `sslmode=require`)" because the TLS mode
never reached the backend:

- ConnectionFormData carried no ssl_* fields and both submit handlers
  (NewConnectionScreen.buildPayload, EditConnectionModal save + test) omitted
  them, so the SSH/SSL tab's mode was silently dropped before IPC.
- SslFields wrote ssl_ca_cert / ssl_client_cert / ssl_client_key — names the
  Rust ConnectionInput ignores (it expects ssl_ca_path / ssl_cert_path /
  ssl_key_path).
- parseConnectionString ignored query params, so a pasted Neon/Supabase URL's
  ?sslmode=require was discarded.

Pasting a URI now fills every setting it can (sslmode / ssl-mode, including
MySQL's REQUIRED and VERIFY_IDENTITY spellings) and offers a derived label
(database name, else host/file stem) as a placeholder that Test/Save uses when
the field is left blank. Managed presets pre-select their TLS mode (Supabase /
Neon → Require, PlanetScale → Verify Full).

Backend safety net: db::tls::resolve_ssl_mode defaults *.neon.tech /
*.supabase.co / *.psdb.cloud to `require` when a connection has no ssl_mode, so
connections saved before this fix keep working; an explicit mode (including
disable) always wins.

Tests: +15 frontend (parser, form payload, SSL field names, edit modal),
+4 Rust (resolve_ssl_mode / tls_decision_for).

AGENTS.md

@@ -239,7 +239,7 @@ Planned work is prioritized in the [Project Roadmap](./ROADMAP.md) (source of tr
 | :--- | :---: | :--- |
 | Connections CRUD (PostgreSQL, MySQL, SQLite, Redis, MariaDB) | ✅ | Full create/read/update/delete with form validation |
 | MariaDB connections | ✅ | First-class db_type on the MySQL driver path (v0.8.0) |
-| New Connection screen (revamped) | ✅ | Two-stage entry → configured flow: Connection URI + 6-card provider grid (PostgreSQL / MySQL / SQLite / Redis / Supabase / NeonDB) with an OR divider → expands into label + tags/env/folder + General|SSH·SSL tabs. Supabase & NeonDB are managed-PostgreSQL presets (persist as `postgresql`) with in-app setup guides + SSL hints; PlanetScale is a managed-MySQL (Vitess) preset (persists as `mysql`) with a setup guide + `.psdb.cloud` host detection (v0.8.0); SQLite swaps the URI field for a file-path + Browse input (v0.7.0) |
+| New Connection screen (revamped) | ✅ | Two-stage entry → configured flow: Connection URI + 6-card provider grid (PostgreSQL / MySQL / SQLite / Redis / Supabase / NeonDB) with an OR divider → expands into label + tags/env/folder + General|SSH·SSL tabs. **Pasting a URI fills every setting it can** — type, host, port, user, password, database, `?sslmode=`/`ssl-mode=` (Neon/Supabase → Require, MySQL `VERIFY_IDENTITY` → verify-full) — and offers a URL-derived label (database name, else host) as a placeholder that Save/Test uses when the field is left blank; Supabase & NeonDB are managed-PostgreSQL presets (persist as `postgresql`) with in-app setup guides + SSL hints, PlanetScale is a managed-MySQL (Vitess) preset (persists as `mysql`) with a setup guide + `.psdb.cloud` host detection (v0.8.0); presets pre-select their TLS mode (Supabase/Neon Require, PlanetScale Verify Full); SQLite swaps the URI field for a file-path + Browse input (v0.7.0)
 | Connection testing (all DB types) | ✅ | PostgreSQL, MySQL, SQLite, Redis all testable |
 | DB Viewer: PostgreSQL browse + query | ✅ | Schemas, tables, paginated data, FK preview, JSON viewer |
 | DB Viewer: SQLite browse + query | ✅ | Full support via rusqlite |
@@ -249,8 +249,8 @@ Planned work is prioritized in the [Project Roadmap](./ROADMAP.md) (source of tr
 | Enable keychain toggle | ✅ | Default ON (opt-out); OFF = don't persist the DB password (session-only, re-prompt on connect) + purge existing keychain entry; SSH secrets stay keychain-only (v0.7.6) |
 | SSH tunnel config UI | ✅ | Host, port, user, auth method, key path, passphrase fields |
 | SSH tunnel runtime | ✅ | Real ssh2 tunnel (password + key auth), binds 127.0.0.1 only, secrets in OS keychain (`ssh_password:<id>` / `ssh_passphrase:<id>`), closed on pool eviction / app exit; TLS downgraded to `require` through the tunnel |
-| SSL/TLS config UI | ✅ | Mode (disable/require/verify-ca/verify-full), cert paths |
-| SSL/TLS runtime | ✅ | PostgreSQL all modes via rustls (disable/require/verify-ca/verify-full; **v1: `verify-ca` behaves as `verify-full`** — documented refinement), client certs PKCS#1/PKCS#8/EC, encrypted client keys rejected; MySQL test path maps modes (verify-full → VerifyIdentity) |
+| SSL/TLS config UI | ✅ | Mode (disable/require/verify-ca/verify-full), cert paths. Selections (mode + CA/client cert/key) are persisted on create **and** edit — the form data type carries the `ssl_*` fields and the submit handlers pass them through (previously the SSH/SSL tab's values were dropped, so connections saved with TLS off and managed providers rejected them) |
+| SSL/TLS runtime | ✅ | PostgreSQL all modes via rustls (disable/require/verify-ca/verify-full; **v1: `verify-ca` behaves as `verify-full`** — documented refinement), client certs PKCS#1/PKCS#8/EC, encrypted client keys rejected; MySQL test path maps modes (verify-full → VerifyIdentity). Managed hosts (`*.neon.tech` / `*.supabase.co` / `*.psdb.cloud`) default to `require` when the connection has no `ssl_mode` (`db::tls::resolve_ssl_mode`), so pre-fix saved connections still connect; an explicit mode always wins |
 | Roles & grants (PG) | ✅ | Create/edit/drop PostgreSQL roles and GRANT/REVOKE privileges per object class from a UI (v0.7.7) |
 
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