fix: extract hardcoded English strings to i18n system with Russian translations

- Extract ~40 hardcoded strings from project detail, deploy, settings, credentials, registries, auth, env editor pages
- Add corresponding Russian translations
- Replace native confirm() default labels with i18n keys in ConfirmDialog
- Fix InstanceCard pluralization to use i18n

web/src/routes/projects/+page.svelte

@@ -48,7 +48,7 @@
 							description: alreadyAdded ? undefined : reg.name,
 							group: reg.name,
 							disabled: alreadyAdded,
-							disabledHint: alreadyAdded ? 'Already added' : undefined
+							disabledHint: alreadyAdded ? $t('projects.alreadyAdded') : undefined
 						});
 					}
 				} catch {
@@ -184,8 +184,8 @@
 					onselect={selectPickedImage}
 					onclose={() => { showImagePicker = false; }}
 				/>
-				<FormField label={$t('projects.port')} name="port" type="number" bind:value={formPort} helpText="Auto-detected from EXPOSE if empty" />
-				<FormField label={$t('projects.healthcheck')} name="healthcheck" bind:value={formHealthcheck} placeholder="/api/health" helpText="Auto-detected from image if empty" />
+				<FormField label={$t('projects.port')} name="port" type="number" bind:value={formPort} helpText={$t('projects.portHelpText')} />
+				<FormField label={$t('projects.healthcheck')} name="healthcheck" bind:value={formHealthcheck} placeholder="/api/health" helpText={$t('projects.healthcheckHelpText')} />
 			</div>
 
 			<div class="mt-6 flex justify-end">