[growlf]

Closes #442

What & why

opskit go's fzf picker was hard to read and could self-terminate:

• No columns — it fed fzf f"{rel}\t{path}" with no header and no fixed widths, so the tab expanded to a tab stop and the long absolute path dominated each line.
• 60s timeout — fzf was invoked with timeout=60; waiting longer killed it, printed "fzf not found or timed out", and exited 1.

Changes (bin/opskit-go.py)

• Added pure helpers: _picker_header(), _picker_row(proj, git_lookup), build_picker(projects, git_lookup=_git_info). Rows are space-padded to fixed widths with a header: NAME | BRANCH | STATUS | RESUME; long values truncate with ….
• Rewrote run_fzf_selection to use --delimiter=\t --with-nth=2 --accept-nth=1 --header=<header>: display the aligned columns, return the hidden path (field 1). The path is parsed with a .split("\t")[0] fallback so it works even on a build that ignores --accept-nth.
• Removed the timeout — Esc/Ctrl+C cancels (nonzero fzf exit → None). fzf-missing still errors clearly.
• Branch/dirty are computed lazily via _git_info for the displayed (enabled) rows only, so the scan stays cheap.

Verification

• New tests/test_tui_picker.py: header names the columns; header/row column offsets align; [resume] only when present; long names truncate to width; each line's field 1 is the path; run_fzf_selection passes no timeout and passes the column options; cancel/empty selection return None.
• make test → 1685 passed, 1 skipped.
• Rendered the real picker block and confirmed aligned columns; smoke-tested fzf accepts the options.

Plan: plans/442-opskit-go-picker-columns.md.

[growlf]

Reviewed. Reproduced both defects against the current code and confirmed the fix.

• Columns. Rendered the real picker block — NAME | BRANCH | STATUS | RESUME line up under a header and the absolute path is hidden. fzf's --with-nth scopes the fuzzy search to the visible columns, so you search NAME (the rel selector), not the hidden path. That's the right behaviour and the plan says so.
• Timeout. The timeout=60 is gone; Esc/Ctrl+C cancels via fzf's nonzero exit and returns None. fzf-missing still errors clearly.
• Selection value. --accept-nth=1 returns the path, with a .split("\t")[0] fallback so an older fzf that ignores --accept-nth still yields the path.

Tests cover the header, column alignment (offsets match), the [resume] flag, truncation to width, path-as-field-1, the no-timeout assertion, and cancel/empty → None. make test → 1685 passed, 1 skipped. CI green.

No blocking issues. Nit only: branch/dirty are recomputed for the selected row on the confirmation screen — negligible for an enabled list. Merging.