fix(updates): always serialize is_held so client filter sees explicit false

Per Copilot review on PR #67: the dashboard's `_applyPkgViewFilter('updates')`
applies a Tabulator filter of `is_held = false`, which uses strict equality.
With `json:"is_held,omitempty"` the agent dropped the field when false, so rows
from `/api/os-updates/packages/installed` arrived with `is_held === undefined`
and got filtered out of the Updates view — making it incomplete after a full
package-list load while `Update All (N)` kept counting them.

Drop omitempty on both Package.IsHeld and InstalledPackage.IsHeld (agent + dashboard
mirror) so the boolean is always on the wire. Adds ~14 bytes/package for a typical
"All Packages" load (~10 KB on a 600-package list) — negligible vs the correctness
fix.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: sarg3nt

gearbox-agent/internal/gears/updates/updates.go

@@ -38,7 +38,10 @@ type Package struct {
 	AvailableVersion string `json:"available_version"`
 	Architecture     string `json:"architecture"`
 	IsSecurityUpdate bool   `json:"is_security_update"`
-	IsHeld           bool   `json:"is_held,omitempty"` // Package is held (pinned via apt-mark/dpkg) — apt will not upgrade it even though a newer version is available
+	// Always serialize is_held — the dashboard filters on `is_held === false`,
+	// so `omitempty` (dropping the field for false values) would cause those
+	// rows to be filtered out by strict-equality checks on the client.
+	IsHeld           bool   `json:"is_held"` // Package is held (pinned via apt-mark/dpkg) — apt will not upgrade it even though a newer version is available
 	Priority         string `json:"priority"`          // low, medium, high, critical
 	Repository       string `json:"repository"`
 	Size             int64  `json:"size_bytes"`    // Download size in bytes
@@ -58,7 +61,7 @@ type InstalledPackage struct {
 	UpdateAvailable  bool      `json:"update_available,omitempty"`
 	AvailableVersion string    `json:"available_version,omitempty"`
 	IsSecurityUpdate bool      `json:"is_security_update,omitempty"`
-	IsHeld           bool      `json:"is_held,omitempty"` // Package is held (pinned) by dpkg/apt-mark
+	IsHeld           bool      `json:"is_held"` // Package is held (pinned) by dpkg/apt-mark — always serialized (see note on Package above)
 	PackageURL       string    `json:"package_url,omitempty"` // Link to package info page
 }
 

gearbox/internal/framework/agent/models.go

@@ -666,7 +666,7 @@ type Package struct {
 	AvailableVersion string `json:"available_version"`
 	Architecture     string `json:"architecture"`
 	IsSecurityUpdate bool   `json:"is_security_update"`
-	IsHeld           bool   `json:"is_held,omitempty"` // Held packages (apt-mark/dpkg pinned) won't be upgraded even when a newer version is available.
+	IsHeld           bool   `json:"is_held"` // Held packages (apt-mark/dpkg pinned) won't be upgraded even when a newer version is available. Always serialized so the dashboard's strict-equality filter (`is_held === false`) sees the explicit value.
 	Priority         string `json:"priority"`
 	Repository       string `json:"repository"`
 	Size             int64  `json:"size_bytes"`
@@ -832,7 +832,7 @@ type InstalledPackage struct {
 	UpdateAvailable  bool   `json:"update_available,omitempty"`
 	AvailableVersion string `json:"available_version,omitempty"`
 	IsSecurityUpdate bool   `json:"is_security_update,omitempty"`
-	IsHeld           bool   `json:"is_held,omitempty"`
+	IsHeld           bool   `json:"is_held"` // Always serialized — see note on Package.IsHeld above.
 	PackageURL       string `json:"package_url,omitempty"`
 }