document.getElementById can return null, but ReactDOM.createRoot requires
a non-null container. Add a guard with a clear error message to prevent
a confusing runtime crash if the element is missing.

Resolves Copilot review comment on index.tsx lines 6-7.

holdAnnotations was typed as literal 'null', preventing actual hold annotations
from being represented and making the imported HoldAnnotations type unused.
Changed to Nullable<HoldAnnotations> for proper type support.

Resolves Copilot review comment on apiFlightplan.ts lines 1-29.

…oint

Import was using internal path @microsoft/signalr/dist/esm/HubConnection
which can break with dependency/bundler changes. Changed to the public
@microsoft/signalr entrypoint for upgrade safety.

Resolves Copilot review comment on HubContext.tsx line 30.

Replace placeholder clientVersion '1.3.0' with VERSION constant,
hardcoded eramSectorId 99 with actual position config value,
clientName 'vTDLS' with 'vFDIO', and hardcoded hasEramConfig with
actual position config check.

Resolves Copilot + jlefkoff review comments on HubContext.tsx lines 134-136.

- Remove references to non-existent files (useCustomFlightplanCommands.ts,
  FlightplanVisualization.tsx)
- Remove AI-generated filler sections (Features, Integration, Data Sources,
  Status Display) that don't provide useful reference information
- Rename 'Files Created' to 'Files' since these are existing files
- Keep command reference content that is useful for end-users

Resolves CrazyKidJack + Copilot review comments on CUSTOM_FLIGHTPLAN_COMMANDS.md.

Improves load performance by allowing the browser to show fallback text
while the custom FDIO font loads, preventing invisible text (FOIT).

Resolves Copilot review comment on terminal.css lines 3-6.

Login failure handlers were logging the same message to both toast.error()
and console.log(). Keep only toast.error() (which already calls
console.error internally) to avoid redundant output.

Resolves jlefkoff review comment on authSlice.ts lines 167-168.

vatsimTokenSelector was a zero-arg function reading directly from
localStorage, bypassing Redux state and causing type issues with
useSelector. Changed to proper (state: RootState) => T selector
shape using state.auth.vatsimToken (which is already synced with
localStorage in thunks/reducers).

Resolves Copilot review comment on authSlice.ts lines 209-214.

ensureConnected was returning the original (stale) hubConnection reference
after calling connectHub(), which meant it would always return null when
starting from a null connection. Changed to accept a getter function
() => HubConnection | null so it can retrieve the updated ref after
connectHub() populates it.

Resolves Copilot review comment on hubUtils.ts lines 6-19.

HubContext was created with a non-null default value, making the
null-guard in useHubConnector ineffective (useContext would never
return falsy). Changed createContext default to null so the runtime
check in useHubConnector properly detects missing Provider.

Resolves Copilot review comment on useHubConnector.ts lines 6-10.

EramTrackDto, ApiAircraftTrack interfaces and updateTrackThunk,
deleteTrackThunk were placeholder stubs with no subscribers to track
topics. Also removed placeholder console.log statements and AI-generated
comments from remaining thunks.

Resolves jlefkoff review comment on apiTypes/index.ts lines 3-13.

These are junk files inserted by WSL that should never be committed.
Added *Zone.Identifier pattern to .gitignore to prevent future occurrences.

Resolves jlefkoff review comment about .Zone.Identifier files.

- Delete windowThunks.ts (no window system implemented)
- Delete SocketContext.tsx (empty stub, not doing shared-state)
- Delete useSocketConnector.ts (console.log-only stub)
- Remove all imports and usages from HubContext.tsx

Resolves jlefkoff review comments on windowThunks.ts and SocketContext.tsx.

Fail fast with a clear error listing any missing env vars instead of
silently running with undefined values that cause confusing errors later.

Resolves jlefkoff review comment on constants.ts lines 1-4.

Every line in the file was duplicated on the same line (e.g.,
'import X;import X;'). Deduplicated all lines and cleaned up
extra blank lines that were artifacts of the corruption.

Resolves jlefkoff review comment on customFlightplanCommandParser.ts.

Remove placeholder comments like 'Simple toast for now', 'Add properties
as needed', 'For development, use alert', 'end blinking cursor section',
and aspirational TODO comments that don't add value.

Keep domain-specific comments that explain ERAM formatting and column
positions since those provide genuine documentation value.

Resolves jlefkoff review comment to remove bogus AI-inserted comments.

Move parseCommand function and all command handlers (FP, AM, GI, WR, SR,
FR, RS) from App.tsx into src/services/commandParser.ts as individual
functions. App.tsx now imports parseCommand and passes a CommandContext
object with all required dependencies. Follows EDST frontend pattern of
dedicated handler functions per command type.

Remove sendEramMessage from HubContext public API and merge its logic
into sendCommand. Remove ProcessEramMessageDto, EramMessageProcessingResultDto,
and EramPositionType imports. Delete src/types/apiTypes/eramTypes.ts (done in
previous commit). Hub message now uses inline object literal instead of typed DTO.