remove em-dash from TODO

TODO.md

@@ -328,54 +328,6 @@ cosmetic label. Worth it once we want trustworthy timestamps (e.g. for
 screenshots, or to stop conflating "live" with "last close"); not
 before.
 
-## Audit: em-dash sentinel usage across all tables - priority LOW
-
-The codebase uses `-` (em-dash) as the canonical "no data" sentinel
-in several table cells, but the rendering rules and alignment
-choices are inconsistent. AGENTS.md now warns against em-dash
-overuse generally; this audit is the second half - pick a
-consistent treatment and apply it everywhere.
-
-Known em-dash sites:
-
-- `src/views/projections.zig` (back-test): hard-coded `dash_cell`
-  literal in 10-col cells - pre-shaped at compile time so no
-  helper is involved. Numeric cells use Zig's `{s:>10}` byte-
-  padding (safe since they're pure ASCII).
-- `src/commands/history.zig` / `src/tui/history_tab.zig`: centered
-  via `fmt.centerDash` in 31-col cells (illiquid totals on
-  imported-only history rows).
-- `src/commands/milestones.zig`: right-padded via
-  `fmt.padRightToCols` in the "days since prev" cell. Mixes
-  with ASCII cells like `"42 days"`.
-- `src/commands/perf.zig` / `src/tui/performance_tab.zig`:
-  emitted via `{s:>13}` byte-padding - under-padded by 2 cols
-  per em-dash. Either hard-code a `dash_cell` literal (cell
-  width is static) or migrate to `fmt.centerDash` /
-  `fmt.padRightToCols`.
-
-Decisions to make:
-
-1. **Centered vs right-aligned in numeric columns.** Back-test
-   centers; perf right-aligns (or would, if it weren't broken).
-   Centering reads as a more deliberate sentinel; right-aligning
-   keeps the visual right-edge of the column smooth. Pick one.
-2. **Should some tables drop the em-dash entirely** in favor of
-   ASCII `-`? Rule of thumb: if the column header makes the
-   meaning unambiguous AND no rows contain bare `-` for other
-   reasons (signed values use `-2.21%` which is multi-char, so
-   a lone `-` is unambiguous), `-` is fine. If the column also
-   carries dates or strings where a stray `-` could read as
-   part of the value, keep `-`.
-3. **Helper vs literal.** When the cell width is fixed and the
-   dash position is static, a hard-coded literal const string
-   (like back-test's `dash_cell`) is simpler than calling a
-   helper at runtime. Use helpers when width or position varies.
-
-Once decisions are made, sweep all four sites + add a regression
-alignment test per table that mixes a fully-populated row with
-an em-dash-heavy row and verifies `displayCols` matches.
-
 ## Analysis: dividend equity / income-shaped equity - think about it
 
 Dividend-equity ETFs (SCHD, VYM, DGRO, NOBL, SDY, VIG, etc.)