Say when a paused dashboard was frozen, so it cannot be mistaken for a hung one

docs/modules-reference.md

@@ -19,7 +19,7 @@ Per-file reference for the refactored tree, plus the shared data structures.
 | [include/fgc/HardwareChecks.h](../include/fgc/HardwareChecks.h), [src/core/HardwareChecks.cpp](../src/core/HardwareChecks.cpp) | The verdicts behind `test hardware`: `checkUsbfsMemory`, `checkUsb3Lpm`, `checkI2cFunctionality`, `checkDrivetrainAdopted`. Pure, so the thresholds that encode known-issues #2 and #19 cannot drift unnoticed |
 | [include/fgc/AxisSpeed.h](../include/fgc/AxisSpeed.h), [src/core/AxisSpeed.cpp](../src/core/AxisSpeed.cpp) | `planAxisSpeed` (deg/s -> TMC `VMAX` through `counts_per_deg`) + `vmaxToDegPerSec`. Pure arithmetic; refuses an uncalibrated scale rather than commanding a near-zero speed |
 | [include/fgc/FirmwareConfig.h](../include/fgc/FirmwareConfig.h), [src/core/FirmwareConfig.cpp](../src/core/FirmwareConfig.cpp) | `parseNeedLine` (firmware `NEED` line -> axis + keys) + `planFirmwareConfig` (-> the `SET` lines that answer it). Reports a key it cannot answer separately from one it does not recognise: incomplete `hardware.ini` vs. a firmware newer than the host |
-| [include/fgc/DumpParser.h](../include/fgc/DumpParser.h), [src/core/DumpParser.cpp](../src/core/DumpParser.cpp) | `parseDump` firmware `DUMP` block → `DumpData` (per-axis state + decoded TMC registers/flags); `formatDump` |
+| [include/fgc/DumpParser.h](../include/fgc/DumpParser.h), [src/core/DumpParser.cpp](../src/core/DumpParser.cpp) | `parseDump` firmware `DUMP` block → `DumpData` (per-axis state + decoded TMC registers/flags); `formatDump`. Prefers the firmware's own `reset=` name over any host-side decode - `mcusr` is an AVR bitmask on one board and a plain enum on the other, so a single table cannot be right for both |
 | [include/fgc/DiagParser.h](../include/fgc/DiagParser.h), [src/core/DiagParser.cpp](../src/core/DiagParser.cpp) | `parseDiag` firmware `DG` self-test stream → `DiagResult` (per-axis tests, PASS/FAIL); `formatDiag` |
 | [include/fgc/Calibration.h](../include/fgc/Calibration.h), [src/core/Calibration.cpp](../src/core/Calibration.cpp) | `linearFit` (least-squares, R²) + `circularMeanDeg` for the IMU-referenced calibration |
 | [include/fgc/PitchSetup.h](../include/fgc/PitchSetup.h), [src/core/PitchSetup.cpp](../src/core/PitchSetup.cpp) | `gimbal pitch setup` worker thread: home-if-needed → pitch sweep dwelling on the gravity-referenced IMU pitch → least-squares fit → park level; tunable via `CalibParams`; exposes `progress()`/`report()`/`takeResult()`. Yaw is not touched |

include/fgc/DumpParser.h

@@ -66,7 +66,19 @@ struct DumpData {
     bool                     valid = false;
     std::string              build;
     long                     uptime_ms = 0;
+    // Why the MCU last restarted, as the firmware reported it.
+    //
+    // `mcusr` is the RAW value and means DIFFERENT THINGS per board: on AVR it is
+    // the MCUSR bitmask (bit 0 power-on, bit 1 external, ...); on RP2040 it is
+    // rp2040.getResetReason(), a plain enum where 3 is one value, not two bits.
+    // Decoding one as the other is silently wrong - it reported an RP2040 soft
+    // reset as "PORF (power-on), EXTRF (external)" on tower 121.
+    //
+    // So the firmware now NAMES it in the dump (`reset=<text>`), and that text is
+    // authoritative because only the board knows its own encoding. reset_flags is
+    // the legacy AVR bit decode, kept for firmware that predates the field.
     unsigned                 mcusr = 0;
+    std::string              reset_text;   // empty => firmware did not name it
     long                     free_ram = 0;
     std::vector<std::string> reset_flags;
     std::vector<DumpAxis>    axes;

include/fgc/ui/TuiUi.h

@@ -3,6 +3,7 @@
 #include "fgc/ui/IUserInterface.h"
 
 #include <atomic>
+#include <chrono>
 #include <deque>
 #include <mutex>
 #include <string>
@@ -46,7 +47,15 @@ private:
     std::atomic<bool> running_{false};
     // When set, the 100ms auto-redraw is suspended so the screen holds still and
     // the operator can select/copy text (terminals drop a selection on repaint).
+    // Display freeze (the `p` key), for selecting text out of the pane. While
+    // set, refreshLoop() stops posting redraws, so the frame on screen ages.
+    // paused_at_ is when it was frozen, so the badge can say how stale it is.
     std::atomic<bool> paused_{false};
+    // Wall-clock time of the freeze, "HH:MM:SS", shown in the badge. Captured
+    // once: the badge must stay truthful WITHOUT a repaint, because repainting
+    // would pull the live snapshot and unfreeze what the pause is holding still.
+    std::string paused_at_hms_;
+    static std::string nowHms();
     // True while the gimbal overlay is open, so the refresh loop can periodically
     // re-pull a firmware dump (keeps the tracking counters ticking without 'd').
     std::atomic<bool> gimbal_overlay_open_{false};

src/core/DumpParser.cpp

@@ -119,6 +119,7 @@ DumpData parseDump(const std::string& block) {
     d.uptime_ms  = asInt(get(hdr, "uptime", "0"));
     d.mcusr      = static_cast<unsigned>(asInt(get(hdr, "mcusr", "0")));
     d.free_ram   = asInt(get(hdr, "free_ram", "0"));
+    d.reset_text  = get(hdr, "reset");
     d.reset_flags = bitsSet(d.mcusr, kMcusr);
 
     // Per-axis lines: "DUMP <Y|P> state=.." and "DUMP <Y|P> TMC ..".
@@ -199,8 +200,17 @@ std::vector<std::string> formatDump(const DumpData& d) {
     }
     {
         std::ostringstream os;
-        os << "reset cause (mcusr=0x" << std::hex << d.mcusr << std::dec << "): "
+        os << "reset cause (0x" << std::hex << d.mcusr << std::dec << "): ";
-           << join(d.reset_flags);
+        if (!d.reset_text.empty()) {
+            // The firmware named it, so no guessing is involved.
+            os << d.reset_text;
+        } else {
+            // Firmware predating the `reset=` field. The only decode available is
+            // the AVR one, and on a non-AVR board it is wrong - so say that it is
+            // an assumption rather than stating it as fact.
+            os << join(d.reset_flags) << "  [assumed AVR MCUSR bits; firmware does "
+                                         "not name it]";
+        }
         out.push_back(os.str());
     }
     for (const auto& ax : d.axes) {

src/ui/TuiUi.cpp

@@ -1,5 +1,7 @@
 #include "fgc/ui/TuiUi.h"
 
+#include <ctime>
+
 #include "fgc/ChannelTopics.h"
 
 #include "fgc/DumpParser.h"
@@ -1247,13 +1249,30 @@ void TuiUi::pushLog(LogLevel level, const std::string& line) {
     }
 }
 
+// Wall-clock time the frame was frozen at, "HH:MM:SS". Captured once, because
+// the badge must not need a repaint to stay truthful - repainting would unfreeze
+// the very data the pause is holding still.
+std::string TuiUi::nowHms() {
+    const auto t = std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());
+    std::tm tm{};
+    localtime_r(&t, &tm);
+    char buf[16];
+    std::strftime(buf, sizeof(buf), "%H:%M:%S", &tm);
+    return buf;
+}
+
 void TuiUi::refreshLoop() {
     using namespace std::chrono_literals;
     auto last_dump = std::chrono::steady_clock::now();
     while (running_) {
         std::this_thread::sleep_for(100ms);
         if (!running_) break;
-        if (paused_) continue;  // frozen for text selection; don't repaint
+        // Frozen for text selection: do NOT repaint. Re-rendering would pull the
+        // live snapshot and the numbers would keep moving under the cursor,
+        // which is precisely what the freeze exists to prevent. The badge
+        // carries the wall-clock time of the freeze instead, so the frame says
+        // how old it is without having to be redrawn to say it.
+        if (paused_) continue;
         // While the gimbal overlay is open, re-pull a firmware dump every ~3s so
         // the encoder-tracking counters stay current without pressing 'd'.
         if (gimbal_overlay_open_.load() && sink_ &&
@@ -1332,7 +1351,15 @@ void TuiUi::uiLoop() {
             text("  " + s.header.tower + "  ") | bold,
             text("build " + s.header.build) | dim,
             filler(),
-            (paused_ ? text(" PAUSED ") | color(Color::Black) | bgcolor(Color::Yellow) | bold
+            // A frozen frame has to say that it is frozen, and for how long.
+            // Without the age it is indistinguishable from a hung program: the
+            // numbers simply stop, which during a multi-minute home reads as a
+            // crash. Costing 15 minutes of "is it stuck?" is how this got added.
+            // Says WHEN it froze, not just that it is frozen. Without the time a
+            // held frame is indistinguishable from a hung program - the numbers
+            // simply stop - which during a multi-minute home reads as a crash.
+            (paused_ ? text(" PAUSED @" + paused_at_hms_ + " ")
+                           | color(Color::Black) | bgcolor(Color::Yellow) | bold
                      : text("")),
             text(" " + mode + " ") | (s.header.live ? color(Color::Green) : color(Color::Yellow)) | bold,
             text("  up " + std::to_string(s.header.uptime_ms / 1000) + "s ") | dim,
@@ -1649,6 +1676,7 @@ void TuiUi::uiLoop() {
         }
         if (c == "p") {  // freeze/unfreeze the live refresh so text can be selected
             paused_ = !paused_;
+            if (paused_) paused_at_hms_ = nowHms();
             return true;  // this keypress redraws once so the indicator updates
         }
         if (overlay == Overlay::Help) {  // vim-style section nav while help is open

tests/test_dumpparser.cpp

@@ -223,3 +223,40 @@ TEST_CASE("the numeric state codes did not shift when NEEDCFG was added") {
     CHECK(one(4) == "ERROR");
     CHECK(one(5) == "NEEDCFG");
 }
+
+TEST_CASE("the firmware's own name for the reset cause wins over any decode") {
+    // mcusr means different things per board: an AVR MCUSR bitmask, or the
+    // RP2040's getResetReason() enum. 0x3 is "two bits set" on one and a single
+    // enum value on the other, so a host-side table cannot be right for both.
+    const std::string text =
+        "DUMP BEGIN build=x uptime=1 mcusr=0x3 reset=SOFT_RESET free_ram=4096\n"
+        "DUMP Y state=1 hsub=0 enabled=0 lim_neg=0 lim_pos=0 hold_target=0 speed=1 center=0 "
+        "soft_margin=0 hold_corr=0 hold_peak=0 hold_cumul=0 has_encoder=1\n"
+        "DUMP END\n";
+    auto d = fgc::parseDump(text);
+    REQUIRE(d.valid);
+    CHECK(d.reset_text == "SOFT_RESET");
+
+    std::string out;
+    for (const auto& l : fgc::formatDump(d)) out += l + "\n";
+    CHECK(out.find("SOFT_RESET") != std::string::npos);
+    // The AVR names must not appear when the firmware said what it was.
+    CHECK(out.find("PORF") == std::string::npos);
+    CHECK(out.find("EXTRF") == std::string::npos);
+}
+
+TEST_CASE("without that field the AVR decode is labelled as an assumption") {
+    const std::string text =
+        "DUMP BEGIN build=old uptime=1 mcusr=0x3 free_ram=4096\n"
+        "DUMP Y state=1 hsub=0 enabled=0 lim_neg=0 lim_pos=0 hold_target=0 speed=1 center=0 "
+        "soft_margin=0 hold_corr=0 hold_peak=0 hold_cumul=0 has_encoder=1\n"
+        "DUMP END\n";
+    auto d = fgc::parseDump(text);
+    REQUIRE(d.valid);
+    CHECK(d.reset_text.empty());
+
+    std::string out;
+    for (const auto& l : fgc::formatDump(d)) out += l + "\n";
+    CHECK(out.find("PORF") != std::string::npos);      // still decoded
+    CHECK(out.find("assumed AVR") != std::string::npos);  // but not stated as fact
+}