feat: connect local Obsidian vaults to conversations

Users can now read, search, and update existing local Obsidian notes through
built-in tools without configuring an external MCP server or Obsidian plugin.
Add vault discovery, an optional folder scope, and independent test, save,
enablement, and runtime assignment controls in MCP settings.

Bundle MCPVault 0.16.0 and its runtime dependencies, exposing 19 shared tools
to direct models and managed local OpenCode and Continue conversations.
Obsidian is disabled by default. Ask remains read-only; Execute permits
writes. Scope and assignment changes revoke existing Obsidian grants.
DeepSeek Harness and remote execution remain unsupported.

Validate the isolated staged snapshot with its own dependency installation:
typecheck, lint, production build, and 540 tests across 14 files passed.
No paid model calls were repeated. Physical-offline, installer, and other
platform acceptance remain pending as documented in the feature record.

Release note: Connect local Obsidian vaults in MCP settings to find notes and
write conversation results back to them. Test all registered vaults or a
chosen folder before enabling access; no Obsidian plugin is required.

src/shared/capability-contracts.ts

@@ -39,7 +39,8 @@ export const builtinMcpServerIdSchema = z.enum([
   'knowledge-base',
   'magic-notes',
   'goodbuddy-config',
-  'builtin-browser'
+  'builtin-browser',
+  'obsidian'
 ])
 export type BuiltinMcpServerId = z.infer<
   typeof builtinMcpServerIdSchema
@@ -365,6 +366,21 @@ export type WebSearchCapability = z.infer<
   typeof webSearchCapabilitySchema
 >
 
+export const obsidianSettingsSchema = z
+  .object({ vaultPath: z.string().trim().max(4096).default('') })
+  .strict()
+export type ObsidianSettings = z.infer<typeof obsidianSettingsSchema>
+
+export const obsidianConnectionTestResultSchema = z.object({
+  vaults: z.array(z.object({
+    id: z.string(),
+    name: z.string(),
+    path: z.string()
+  }).strict()),
+  toolCount: z.number().int().min(0)
+}).strict()
+export type ObsidianConnectionTestResult = z.infer<typeof obsidianConnectionTestResultSchema>
+
 export const capabilitySnapshotSchema = z
   .object({
     skills: z.array(skillSummarySchema).max(256),
@@ -380,8 +396,9 @@ export const capabilitySnapshotSchema = z
       .optional(),
     builtinMcpServers: z
       .array(builtinMcpServerStateSummarySchema)
-      .max(4)
+      .max(5)
       .optional(),
+    obsidian: obsidianSettingsSchema.default({ vaultPath: '' }),
     mcpServers: z.array(mcpServerSummarySchema).max(64),
     webSearch: webSearchCapabilitySchema.optional(),
     computerCapabilities: z