Commit the Projects/Tasks/Ideas/TaskComments feature

This was already implemented, migrated, and running live, but had
never been committed. Bringing it into git: Project/Task/Idea/
TaskComment models, their JSON API (CRUD + status transitions,
task comments, idea<->project linking), Livewire UI pages, and the
nav/route wiring for them. All 42 of its own tests pass.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/Models/Idea.php

@@ -0,0 +1,103 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\SoftDeletes;
+
+class Idea extends Model
+{
+    use HasFactory, SoftDeletes;
+
+    public const STATUSES = ['new', 'considered', 'planned', 'rejected', 'implemented'];
+
+    public const CATEGORIES = ['feature', 'improvement', 'bugfix', 'research', 'other'];
+
+    protected $fillable = [
+        'title',
+        'description',
+        'status',
+        'project_id',
+        'priority',
+        'category',
+        'tags',
+        'user_id',
+    ];
+
+    protected $casts = [
+        'priority' => 'integer',
+    ];
+
+    public function project(): BelongsTo
+    {
+        return $this->belongsTo(Project::class);
+    }
+
+    public function user(): BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    public function scopeNew($query)
+    {
+        return $query->where('status', 'new');
+    }
+
+    public function scopeConsidered($query)
+    {
+        return $query->where('status', 'considered');
+    }
+
+    public function scopePlanned($query)
+    {
+        return $query->where('status', 'planned');
+    }
+
+    public function scopeRejected($query)
+    {
+        return $query->where('status', 'rejected');
+    }
+
+    public function scopeImplemented($query)
+    {
+        return $query->where('status', 'implemented');
+    }
+
+    public function scopeByCategory($query, string $category)
+    {
+        return $query->where('category', $category);
+    }
+
+    public function scopeLinkedToProject($query)
+    {
+        return $query->whereNotNull('project_id');
+    }
+
+    public function scopeUnlinked($query)
+    {
+        return $query->whereNull('project_id');
+    }
+
+    public function scopeSearch($query, string $search)
+    {
+        return $query->where('title', 'like', '%' . $search . '%')
+            ->orWhere('description', 'like', '%' . $search . '%')
+            ->orWhere('tags', 'like', '%' . $search . '%');
+    }
+
+    public function getTagsArrayAttribute(): array
+    {
+        return $this->tags ? explode(',', $this->tags) : [];
+    }
+
+    public function setTagsAttribute(array|string|null $value): void
+    {
+        if (is_array($value)) {
+            $this->attributes['tags'] = implode(',', $value);
+        } else {
+            $this->attributes['tags'] = $value;
+        }
+    }
+}