Open Planner Studio

A release built around one feature, taken all the way from a first read to full date-fidelity: native MS Project (.mpp) import — plus the mainline work that landed after v2026.8.0 was tagged (the "dates as recorded" mode, the WBS jump button, the active-between filter). About 357 commits since v2026.8.0 in total.

Added

• Open Planner Studio can now open MS Project (.mpp) files natively. The format joins the existing open pipeline — its own registry entry, a lazily loaded parser chunk, translated error messages in all fourteen languages — with no external converter involved: the file's own binary container (a Compound File Binary / OLE2 structure) is parsed directly, then its calendars, tasks, hierarchy, constraints, relations, resources and assignments are read out of it.
• .mpp import is now date-faithful to the minute. Across a 216-file test corpus, every file now lands on exactly zero start, finish and same-day deviations after recalculation — no exceptions — enforced by an always-on regression gate that fails the moment a single pinned file drifts again or picks up an undocumented exception. Getting there took several new pieces of scheduling engine, all shared with the rest of the app rather than bolted onto the .mpp path alone: task splits are now a first-class feature — read from the source file, carried through the critical-path calculation as per-segment remaining work, and drawn as genuinely broken bars in the Gantt chart, the print preview and PDF export; leveling delay is read and applied to the schedule to the minute; timephased (contoured) assignments now walk their own imported date window and duration through the assigned resource's own calendar — holiday-aware, and correctly apportioning work when a task carries more than one simultaneous assignment; manually scheduled tasks follow genuine MS Project semantics, including how their fixed dates propagate to successors; out-of-sequence progress is read from MS Project's own resume/stop fields instead of being inferred; and the critical-path solver gained a handful of matching refinements — an unsnapped raw anchor for root tasks that start exactly on a calendar band boundary, a zero-duration milestone that no longer snaps past its own deadline, and a dedicated rule for resumed out-of-sequence work.

• A "dates as recorded" mode (issue #63): when a file's stored dates differ from what recalculation produces, the app can now show the project exactly as the file recorded it — with its own toolbar strip, an in-app guide article, and a working undo path back to the recalculated schedule. Leaving the mode is explicit: any date-touching edit or a recalculation returns to computed dates.
• A WBS jump button on dependencies (issue #65): every dependency row in the task properties panel now shows the linked task's WBS number as a clickable button — hover for the same details as a Gantt bar tooltip, click to select the task while the chart zooms and scrolls to it, auto-expanding any collapsed parents.
• An "active between" filter field (issue #32): filter tasks on interval overlap with a date range, using both start and finish.

Changed

• Nothing a .mpp file contains is thrown away on import, and edits only ever switch off derived steering — never delete data. Raw contour periods, MS Project's task-type and effort-driven flags, and every other field added for date-fidelity round-trip through the project's IFC file like the rest of the project data. Editing a task that MS Project was actively steering hour by hour never silently drops what was read from the source; it only stops that hour-by-hour distribution from applying going forward, and the underlying data stays in the document.
• Editing a task now says, at the moment you edit it, when the edit releases MS Project's original hour-by-hour distribution. A one-time in-app notice appears the first time this happens in a document, and the task's properties panel carries a small marker so the state stays visible afterwards — both link straight to the relevant section of the MS Project import guide. An AI assistant working through the MCP bridge gets the same signal as a timephasedGuidanceLost field on its response.
• Every user-facing notification in the app is now in-app. The last native browser/OS confirm dialog (removing a resource library company) was replaced by the app's own confirmation dialog; only the file open/save pickers remain native, as they must.
• The .mpp opening notice now counts real signals instead of estimating them, and the MS Project import guides (Dutch and English) were rewritten so each claim points at the code or test that backs it up.

Fixed

• Auto-save could fail on a fresh install because the application data directory did not exist yet (issue #72): the directory is now created before the first auto-save or library write.
• A calendar name collision on IFC round-trip could cross-contaminate two calendars. Timephased duration data translated its resource-calendar reference by calendar name, but the app never enforced calendar names being unique — two identically named calendars with different working hours could silently swap places after a save/reload. The translation now goes through the calendar's own identity instead of its name.
• A finish-no-later-than or start-no-later-than deadline could push a milestone forward past that very deadline. A guard meant to keep those deadline types from affecting forward scheduling ran too early and let a zero-duration milestone snap to (or past) the deadline anyway.
• Duration, date or duration-type edits did nothing on a task whose imported work distribution had already been apportioned across more than one assignment. The frozen, imported values kept winning over the edit; such edits now correctly release that distribution instead of being silently ignored.
• A calendar representing a full day as one continuous band failed to switch into hour-precision mode. Calendars in the "24 Hours" family (one continuous midnight-to-midnight band) were missing a needed signal and silently stayed in day-precision mode, losing hour-level detail for every resource on them. The fix lives in the shared sub-day calendar layer, so it applies to IFC, MSPDI and Primavera imports as well as .mpp — an existing project with such a calendar will now correctly promote to hour precision on open.
• Task durations computed against a non-whole-number workday length (for example 8.4 hours, a value MS Project allows) could land one workday late. A tiny floating-point rounding error was read as "not finished yet" and added an extra workday that shouldn't have been there.

Documentation

• The MS Project import guide (Dutch and English) was rewritten around what the engine actually does now, not what it did at the start of this effort: split tasks are always visible, manually scheduled tasks keep their own dates with no slack by design (not "shows slack"), leveling delay is counted in both directions, and contoured assignments follow their imported window but are not yet recomputed after a manual edit. The WBS guide and the relations/constraints guide each gained a short note on how a manually scheduled task behaves (it doesn't roll up; it wins over a hard pin). The import/export guide now spells out what each export format does with manually-scheduled, leveling-delay, split and resume/stop data — CSV drops it silently, MSPDI and P6 exports warn.