feat(hashline): port hashline edit tool from oh-my-pi

This PR ports the hashline edit tool from oh-my-pi to oh-my-opencode as an experimental feature.

## Features
- New experimental.hashline_edit config flag
- hashline_edit tool with 4 operations: set_line, replace_lines, insert_after, replace
- Hash-based line anchors for safe concurrent editing
- Edit tool disabler for non-OpenAI providers
- Read output enhancer with LINE:HASH prefixes
- Provider state tracking module

## Technical Details
- xxHash32-based 2-char hex hashes
- Bottom-up edit application to prevent index shifting
- OpenAI provider exemption (uses native apply_patch)
- 90 tests covering all operations and edge cases
- All files under 200 LOC limit

## Files Added/Modified
- src/tools/hashline-edit/ (7 files, ~400 LOC)
- src/hooks/hashline-edit-disabler/ (4 files, ~200 LOC)
- src/hooks/hashline-read-enhancer/ (3 files, ~400 LOC)
- src/features/hashline-provider-state.ts (13 LOC)
- src/config/schema/experimental.ts (hashline_edit flag)
- src/config/schema/hooks.ts (2 new hook names)
- src/plugin/tool-registry.ts (conditional registration)
- src/plugin/chat-params.ts (provider state tracking)
- src/tools/index.ts (export)
- src/hooks/index.ts (exports)

src/hooks/anthropic-context-window-limit-recovery/recovery-deduplication.test.ts

@@ -1,6 +1,7 @@
-import { describe, test, expect, mock, beforeEach } from "bun:test"
+import { describe, test, expect, mock, beforeEach, afterAll } from "bun:test"
 import type { PluginInput } from "@opencode-ai/plugin"
 import type { ExperimentalConfig } from "../../config"
+import * as originalDeduplicationRecovery from "./deduplication-recovery"
 
 const attemptDeduplicationRecoveryMock = mock(async () => {})
 
@@ -8,6 +9,10 @@ mock.module("./deduplication-recovery", () => ({
   attemptDeduplicationRecovery: attemptDeduplicationRecoveryMock,
 }))
 
+afterAll(() => {
+  mock.module("./deduplication-recovery", () => originalDeduplicationRecovery)
+})
+
 function createImmediateTimeouts(): () => void {
   const originalSetTimeout = globalThis.setTimeout
   const originalClearTimeout = globalThis.clearTimeout

src/hooks/anthropic-context-window-limit-recovery/storage.test.ts

@@ -1,4 +1,4 @@
-import { describe, test, expect, mock, beforeEach } from "bun:test"
+import { describe, test, expect, mock, beforeEach, afterAll } from "bun:test"
 import { truncateUntilTargetTokens } from "./storage"
 import * as storage from "./storage"
 
@@ -11,6 +11,10 @@ mock.module("./storage", () => {
   }
 })
 
+afterAll(() => {
+  mock.module("./storage", () => storage)
+})
+
 describe("truncateUntilTargetTokens", () => {
   const sessionID = "test-session"