Feature: 'did you mean' suggestions for unknown column/table errors

[vmvarela]

Context

SQLite errors on typos are terse: no such column: emial. The tool knows the real column list (already exposed via getTableColumns / PRAGMA table_info), so a Levenshtein suggestion is cheap and saves a round trip to --columns. #197 already contemplates the same mechanism for parameter names.

Proposed behavior

$ sql-pipe data.csv 'SELECT emial FROM t'
error: no such column: emial
hint:  did you mean 'email'?

• On SQLite no such column: X / no such table: X errors, look up known names and suggest the closest match within edit distance ≤ 2 (scaled for short names).
• Print hint to stderr after the error; exit code unchanged.

Scope (v1)

• Columns of all loaded tables + table names.
• Reuse one small Levenshtein helper for columns, tables, and (when Feature: --param NAME=VAL named SQL parameter binding #197 lands) --param names.

Excluded (YAGNI)

• Suggesting SQL keywords or functions
• Multiple suggestions (one best match is enough)
• Fuzzy auto-correction (hint only, never rewrite the query)

Acceptance criteria

• Typo column produces a 'did you mean' hint on stderr
• Typo table name likewise
• No hint when nothing is within the distance threshold
• Error path and exit code otherwise unchanged
• Unit test for the distance/suggestion helper