feat(P4-003): @mosaic/log — log ingest, parsing, tiered storage

Implement AgentLogsRepo with structured log ingest (single + batch),
flexible query builder (filter by session, level, category, tier,
date range), and tiered storage management (hot→warm→cold→purge).
Add getLogsForSummarization() for the summarization pipeline.
Wire LogModule into gateway with REST endpoints at /api/logs.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/gateway/src/log/log.controller.ts

@@ -0,0 +1,62 @@
+import { Body, Controller, Get, Inject, Param, Post, Query, UseGuards } from '@nestjs/common';
+import type { LogService } from '@mosaic/log';
+import { LOG_SERVICE } from './log.tokens.js';
+import { AuthGuard } from '../auth/auth.guard.js';
+import type { IngestLogDto, QueryLogsDto } from './log.dto.js';
+
+@Controller('api/logs')
+@UseGuards(AuthGuard)
+export class LogController {
+  constructor(@Inject(LOG_SERVICE) private readonly logService: LogService) {}
+
+  @Post()
+  async ingest(@Query('userId') userId: string, @Body() dto: IngestLogDto) {
+    return this.logService.logs.ingest({
+      sessionId: dto.sessionId,
+      userId,
+      level: dto.level,
+      category: dto.category,
+      content: dto.content,
+      metadata: dto.metadata,
+    });
+  }
+
+  @Post('batch')
+  async ingestBatch(@Query('userId') userId: string, @Body() dtos: IngestLogDto[]) {
+    const entries = dtos.map((dto) => ({
+      sessionId: dto.sessionId,
+      userId,
+      level: dto.level as 'debug' | 'info' | 'warn' | 'error' | undefined,
+      category: dto.category as
+        | 'decision'
+        | 'tool_use'
+        | 'learning'
+        | 'error'
+        | 'general'
+        | undefined,
+      content: dto.content,
+      metadata: dto.metadata,
+    }));
+    return this.logService.logs.ingestBatch(entries);
+  }
+
+  @Get()
+  async query(@Query('userId') userId: string, @Query() params: QueryLogsDto) {
+    return this.logService.logs.query({
+      userId,
+      sessionId: params.sessionId,
+      level: params.level,
+      category: params.category,
+      tier: params.tier,
+      since: params.since ? new Date(params.since) : undefined,
+      until: params.until ? new Date(params.until) : undefined,
+      limit: params.limit ? Number(params.limit) : undefined,
+      offset: params.offset ? Number(params.offset) : undefined,
+    });
+  }
+
+  @Get(':id')
+  async findOne(@Param('id') id: string) {
+    return this.logService.logs.findById(id);
+  }
+}