feat: added ordered systemPrompt arrays and normalized context prompts

- Converted systemPrompt APIs and state types to ordered `string[]` across agent, AI, and coding-agent surfaces.
- Added `normalizeSystemPrompts` and applied it to context normalization before building provider request payloads.
- Updated AI providers to emit separate normalized prompt blocks/messages instead of a single merged system prompt.
- Removed dedicated `projectPrompt` state and remapped that context into system-context buckets in session, dump, and token accounting.
- Aligned tests and changelogs to pass and assert `systemPrompt` as arrays with ordered prompt semantics.

packages/coding-agent/examples/hooks/handoff.ts

@@ -94,7 +94,7 @@ export default function (pi: HookAPI) {
 
 					const response = await complete(
 						ctx.model!,
-						{ systemPrompt: SYSTEM_PROMPT, messages: [userMessage] },
+						{ systemPrompt: [SYSTEM_PROMPT], messages: [userMessage] },
 						{ apiKey, signal: loader.signal },
 					);
 

packages/coding-agent/examples/hooks/qna.ts

@@ -85,7 +85,7 @@ export default function (pi: HookAPI) {
 
 					const response = await complete(
 						ctx.model!,
-						{ systemPrompt: SYSTEM_PROMPT, messages: [userMessage] },
+						{ systemPrompt: [SYSTEM_PROMPT], messages: [userMessage] },
 						{ apiKey, signal: loader.signal },
 					);
 

packages/coding-agent/examples/sdk/03-custom-prompt.ts

@@ -7,8 +7,10 @@ import { createAgentSession, SessionManager } from "@oh-my-pi/pi-coding-agent";
 
 // Option 1: Replace prompt entirely
 const { session: session1 } = await createAgentSession({
-	systemPrompt: `You are a helpful assistant that speaks like a pirate.
+	systemPrompt: [
+		`You are a helpful assistant that speaks like a pirate.
 Always end responses with "Arrr!"`,
+	],
 	sessionManager: SessionManager.inMemory(),
 });
 
@@ -24,11 +26,12 @@ console.log("\n");
 
 // Option 2: Modify default prompt (receives default, returns modified)
 const { session: session2 } = await createAgentSession({
-	systemPrompt: defaultPrompt => `${defaultPrompt}
-
-## Additional Instructions
+	systemPrompt: defaultPrompt => [
+		...defaultPrompt,
+		`## Additional Instructions
 - Always be concise
 - Use bullet points when listing things`,
+	],
 	sessionManager: SessionManager.inMemory(),
 });
 

packages/coding-agent/examples/sdk/README.md

@@ -87,7 +87,7 @@ const { session } = await createAgentSession({
 	model,
 	authStorage: customAuth,
 	modelRegistry: customRegistry,
-	systemPrompt: "You are helpful.",
+	systemPrompt: ["You are helpful."],
 	toolNames: ["read", "bash"],
 	customTools: [{ tool: myTool }],
 	hooks: [{ factory: myHook }],