Objects: one chart evidence paragraph in gaps.md; trendlines are not missing

gaps.md §4 carried two evidence paragraphs, an older one saying PRs #158
and #161 were open and a newer one saying all 2-D kinds survive XLSX round
trip, both repeating the resize, smooth-line, Switch Row/Column and
trendline statements. It is one paragraph with the current status again.

The Mainstream chart row in target-app-parity.md listed trendlines as
missing; they are read, written and drawn (`Series::trendlines`, the XLSX
chart reader and writer, `chart.addElement`), as chart-parity.md records.
The row now says so and keeps "no axis options". No score change.

docs/gaps.md

@@ -45,10 +45,10 @@ No alpha blockers: every core workflow passes the [alpha gate](roadmap.md#alpha-
 ### 4. Charts lose options on round trip; shallow chart model (F, FF)
 - **Missing:** axis scaling, label options, error bars, per-point formatting.
 - **Evidence:** `Chart` holds only title, legend position, two flags and axis titles
-  (`crates/model/src/features.rs`); PRs #158, #161 open; charts resize from eight handles (#190). Smooth lines (#62), Switch Row/Column (#116) and trendlines (read, written, drawn) landed. Multi-level category axes (year beside month) are read, drawn and written back.
   (`crates/model/src/features.rs`); all 2-D kinds survive XLSX round trip (#158, #161); charts
-  resize from eight handles (#190). Smooth lines (#62), Switch Row/Column (#116) and trendlines (read,
-  written, drawn) landed.
+  resize from eight handles (#190). Smooth lines (#62), Switch Row/Column (#116) and trendlines
+  (read, written, drawn) landed. Multi-level category axes (year beside month) are read, drawn
+  and written back.
 - **Impact:** charts are in most business workbooks.
 - **Estimate:** 25–35 h for beta (40–60 h full). [chart-parity.md](chart-parity.md)
 
@@ -183,7 +183,7 @@ No alpha blockers: every core workflow passes the [alpha gate](roadmap.md#alpha-
 
 | Date | Change | Summary |
 |---|---|---|
-| 2026-10-31 | minor | §4: charts, like every floating object, move and resize from eight handles (#190), so resizing is no longer listed as missing |
+| 2026-10-31 | minor | §4: charts, like every floating object, move and resize from eight handles (#190), so resizing is no longer listed as missing; the evidence is one paragraph again, without the stale "PRs #158, #161 open" |
 | 2026-10-24 | minor | §8: PivotTable Enable show details: `pivot.options` `enableShowDetails` turns Show Details off for a PivotTable, read and written in XLSX as `enableDrill` |
 | 2026-10-23 | minor | §8: PivotTable Show Details: double-clicking a value cell lists its source records on a new sheet (#2364) |
 | 2026-10-22 | minor | §20: a native window per workbook window, New Window on the same workbook and Arrange All on the desktop; left: Arrange All across monitors, the web's one window, pen pressure (estimate 10–14 h → 5–8 h) |

docs/target-app-parity.md

@@ -134,7 +134,7 @@ functions, co-authoring and admin, specialist hardware, and languages beyond the
 | Cell formatting, styles, conditional formatting | 13 | 80 | Feature-area table |
 | Sort, filter, tables, validation | 10 | 70 | Feature-area table |
 | PivotTables (core: fields, layouts, grouping, refresh) | 8 | 60 | Slicers and calculated fields excluded as less frequent |
-| Charts (column, bar, line, pie, scatter, combo) | 9 | 45 | Common kinds work and survive save; no axis options or trendlines; moved and resized from eight handles (#190) |
+| Charts (column, bar, line, pie, scatter, combo) | 9 | 45 | Common kinds work and survive save; trendlines read, written and drawn; no axis options; moved and resized from eight handles (#190) |
 | Page layout, print, PDF | 5 | 60 | Latin text exports |
 | Comments, notes, protection | 3 | 55 | Feature-area table |
 | Pictures and shapes | 2 | 45 | Feature-area table |
@@ -334,7 +334,7 @@ The inventory carried over from the 2026-10-07 ROADMAP.md, updated for what land
 
 | Date | Change | Summary |
 |---|---|---|
-| 2026-10-31 | minor | Charts move and resize from eight handles like every floating object (#190): the Essentials chart work is polish only (5–8 h), and the chart rows and the interaction discount no longer list resizing as missing (no score change) |
+| 2026-10-31 | minor | Charts move and resize from eight handles like every floating object (#190): the Essentials chart work is polish only (5–8 h), and the chart rows and the interaction discount no longer list resizing as missing; the Mainstream chart row no longer lists trendlines as missing (no score change) |
 | 2026-10-25 | minor | Automation: macro interface (Automate › Macros, the Macros and Record Macro dialogs, the step editor, shortcuts) (no score change) |
 | 2026-10-25 | trivial | Catalog count 276 / 292 in the summary table and the method, as `cargo xtask parity` measures (no score change) |
 | 2026-10-22 | minor | Several windows on the desktop: a native window per workbook window, New Window on the same workbook, Switch Windows and Arrange All; "one window" removed from UI/UX fidelity, Hardware and the interaction-fidelity discount; no score change |