fix(cli): render Go's caret, Detail, and 42704 hint in migration-apply errors

[Coly010]

What changed

A failed migration statement in db push / db reset (remote migrate) / migration up|down now renders the same failure text as the Go CLI's (*MigrationFile).ExecBatch (apps/cli-go/pkg/migration/file.go:88-132), byte-for-byte:

ERROR: type "ltree" does not exist (SQLSTATE 42704)

Hint: This type may be defined in a schema that's not in your search_path.
      Use schema-qualified type references to avoid this error:
        CREATE TABLE example (col extensions.ltree);
      Learn more: supabase migration new --help
At statement: 0
CREATE TABLE test (path ltree NOT NULL)
                        ^

Previously the TS apply path emitted only <driver text>\nAt statement: <i>\n<stat> — and with the real driver the head line was literally effect/sql/SqlError: Failed to execute statement. No caret, no Detail, no 42704 hint.

• Driver boundary (legacy-db-connection.sql-pg.layer.ts): a server ErrorResponse found on the SqlError cause chain is now rendered as pgconn's PgError.Error() — <Severity>: <Message> (SQLSTATE <Code>) (pgconn errors.go:51) — and LegacyDbExecError carries the structured detail / position fields (detail only when non-empty, position only when > 0, matching Go's gates). Non-server failures keep the driver text verbatim.
• Apply mapper (legacy-migration-apply.ts): legacyMarkError is a byte-faithful port of Go's markError — the server position is consumed against UTF-8 byte lengths (Go's len(line)), the caret line replaces every line after the error line (Go's append(lines[:j+1], caret) truncation), and position 0 / past-end / on-a-line-break leave the statement untouched. All semantics were pinned by running Go's markError directly on the same inputs. The Detail line and the SQLSTATE-42704 undefined-type hint block (gated on Go's typeNamePattern match + code 42704 + not schema-qualified) are reproduced with Go's exact ordering and indentation.
• legacyIsSqlState is hoisted out of legacy-connect-errors.ts's private pattern so the connect-cause renderer and the exec-error mapper share the server-error discriminator.

Behavior notes

• The pgconn-style head line applies to every session exec/query server error, not just migration apply — that is the correct owner (Go's session errors all bottom out in PgError.Error()). This incidentally improves the seed path too: failed to send batch: ERROR: … (SQLSTATE …) now matches Go's SeedFile.ExecBatchWithCache wrap more closely.
• Known, unchanged divergence (out of scope): non-server exec failures (socket drops mid-statement) keep the node driver's own text, which cannot byte-match Go's pgx wording.
• A new wire-level integration test drives the REAL driver stack (fake Postgres server → node-postgres DatabaseError → @effect/sql-pg SqlError chain → the new mapper) so a future @effect/sql-pg/pg bump that changes the error wrapping fails CI instead of silently regressing to the opaque head line.

Review pass (architect / engineer / security / DX): all approve. Deliberately left open: terminal-escape passthrough of server-controlled error text is intended Go parity (Go prints the same fields raw to stderr); a describeLiveDataPlane golden-path test against a real backend was deemed redundant with the new wire-level test.

Fixes CLI-1977
https://linear.app/supabase/issue/CLI-1977/migration-apply-errors-omit-gos-caret-detail-and-42704-extension-hint

[Coly010]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Chef's kiss.

Reviewed commit: edeac810b7

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[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: edeac810b7

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[github-actions]

Supabase CLI preview

npx --yes https://pkg.pr.new/supabase/cli/supabase@dd66eaef37cc2f14b1e5a5539da9c68b2e385b05

Preview package for commit dd66eae.

[Coly010]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Keep it up!

Reviewed commit: dd66eaef37

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

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[kanadgupta]

This is neat!