Fixed Svc/FileWorker: report FW_STATUS_FAILED_TO_WRITE when writeIn's…

[bitWarrior]

Related Issue(s)	PR-5397
Has Unit Tests (y/n)	Y
Documentation Included (y/n)	N
Generative AI was used in this contribution (y/n)	Y

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Change Description

Two independent correctness fixes in Svc/FileWorker, one commit each:

1. writeIn_handler status propagation. writeIn_handler emitted
   FW_STATUS_DONE_WRITE on writeDoneOut unconditionally, even when
   writeBufferToFile returned false (open failure, permission denied, disk
   full, partial write). The return value only gated the hash sidecar write, not
   the reported status. It now reports FW_STATUS_FAILED_TO_WRITE (existing
   enumerator in FileWorkerTypes.hpp) with 0 bytes on failure. Adds
   testWriteErrStatusReported to the error harness, which drives the full
   writeIn port handler with an injected open failure and asserts the failure
   status on writeDoneOut.

2. readFileBytes partial-read telemetry. On a short read, the partially
   transferred bytes were not added to bytesRead before returning
   FW_READ_ERROR, so the ReadError event undercounted the amount actually
   read. bytesRead is now incremented by the real transferred count on that
   path. A short read remains an error (FileWorker reads a fixed, caller-specified
   size and must not silently accept a truncated file) — only the reported count
   is corrected.

Rationale

Both are status/telemetry-reporting correctness bugs. For (1), a downstream
consumer or ground operator keying on the writeDoneOut status is told a write
succeeded when it did not, so the reported status and the on-disk state diverge —
an operationally significant gap during incident investigation. The existing
testWriteErr covered the writeBufferToFile helper's return value and events
but never exercised the handler's writeDoneOut status, which is why this
slipped through. For (2), the corrected byte count makes ReadError telemetry
reflect what was actually transferred.

Testing/Review Recommendations

• fprime-util check on Svc/FileWorker.
• testWriteErrStatusReported is a genuine regression test: it fails against the
  pre-fix source (handler reports DONE_WRITE) and passes with the fix. Run it
  once before and once after applying commit 1 to confirm.
• Reviewer decision point: commit 1 reports 0 bytes on the failure path
  (isWrite ? buffer.getSize() : 0). If retaining buffer.getSize() for
  diagnostics is preferred, the handler and the test's third assertion argument
  change together.
• Fix (2) is telemetry-accuracy only and has no dedicated new test; it affects
  the bytesRead value passed to the existing ReadError event and nothing else.

Future Work

None

AI Usage (see policy)

Claude was used to update the unit tests and to draft this PR.

[github-actions]

Coverage report — base devel

Overall (line): 82.08% → 82.07% (-0.01)
Regression threshold: 0.50% (line).

Regressions

(none over threshold)

Modules changed

Module	Line	Δ	Function	Δ	Branch	Δ
Os/Posix	62.00	-0.40	84.21	+0.00	43.87	-0.23
Os/Generic	89.03	-0.13	88.16	+0.00	73.11	+0.00
Svc/FileWorker	90.35	+0.06	100.00	+0.00	85.54	+0.67
Fw/DataStructures	98.48	+0.27	96.95	-0.19	83.21	+0.37

Modules without UTs

CFDP/Checksum/GTest, Drv/ByteStreamDriverModel, Drv/Interfaces, Drv/LinuxGpioDriver, Drv/LinuxI2cDriver, Drv/LinuxSpiDriver, Drv/LinuxUartDriver, Drv/Ports, Drv/Ports/DataTypes, FppTestProject/FppTest/interfaces, FppTestProject/FppTest/topology/async, FppTestProject/FppTest/topology/components/Comp, FppTestProject/FppTest/topology/components/Framework, FppTestProject/FppTest/topology/components/Receiver, FppTestProject/FppTest/topology/components/Sender, FppTestProject/FppTest/topology/guarded, FppTestProject/FppTest/topology/ports, FppTestProject/FppTest/topology/sync, FppTestProject/FppTest/topology/top_ports, FppTestProject/FppTest/topology/types, Fw/Cmd, Fw/Com, Fw/Comp, Fw/FilePacket/GTest, Fw/Fpy, Fw/Interfaces, Fw/Obj, Fw/Port, Fw/Ports/CompletionStatus, Fw/Ports/Ready, Fw/Ports/Signal, Fw/Ports/SuccessCondition, Fw/Prm, Fw/SerializableFile/test/TestSerializable, Fw/Sm, Fw/Test, Fw/Types/GTest, Os/Models, Svc/Cycle, Svc/DpPorts, Svc/Fatal, Svc/FatalHandler, Svc/FileDownlinkPorts, Svc/FprimeProtocol, Svc/Interfaces, Svc/PassiveConsoleTextLogger, Svc/Ping, Svc/PolyIf, Svc/Ports/CommsPorts, Svc/Ports/FilePorts, Svc/Ports/OsTimeEpoch, Svc/Ports/TlmPacketizerPorts, Svc/Ports/VersionPorts, Svc/Sched, Svc/Seq, Svc/Subtopologies/CdhCore, Svc/Subtopologies/ComCcsds, Svc/Subtopologies/ComFprime, Svc/Subtopologies/ComLoggerTee, Svc/Subtopologies/DataProducts, Svc/Subtopologies/DpCompression, Svc/Subtopologies/FileHandling, Svc/Types/TlmPacketizerTypes, Svc/WatchDog, TestDeploymentsProject/Ref/PingReceiver, TestDeploymentsProject/Ref/RecvBuffApp, TestDeploymentsProject/Ref/SendBuffApp, TestDeploymentsProject/Ref/Top, TestDeploymentsProject/Ref/TypeDemo, cmake/test/data/TestDeployment/TestBuildAutocoder, cmake/test/data/TestDeployment/TestChainedAutocoder, cmake/test/data/TestDeployment/TestHeaderAutocoder, cmake/test/data/TestDeployment/TestTargetAutocoder, cmake/test/data/test-fprime-library/TestLibrary/TestComponent, cmake/test/data/test-fprime-library2/TestLibrary2/TestComponent